The A to Z of Good Personal Finance: My Saving and Investing Philosophy

I wrote the first version of this list back in 2008 — which tells you something: the fundamentals of good personal finance don’t change much. What changes is the context around them. Interest rates, tax rules, available tools. But the underlying principles? Still the same.

A — Avoid paying credit card balances late. You end up paying interest rates that are nearly impossible to out-invest (typically 20–27% APR in 2026), and before long you owe far more than you actually spent. Credit card debt is the most expensive form of debt, the easiest to accumulate, and the first one to eliminate. Credit card companies spend billions acquiring customers who’ll eventually become fee generators. Don’t be that customer.

B — Budgeting. There’s one simple rule to building wealth: spend less than you earn. Most people know roughly what they earn. The problem is tracking where the money actually goes. I’d recommend keeping a budget for at least 3 months to get an honest picture of your spending patterns. Once you know them, you can change them. See my full income and spending roadmap for a step-by-step system.

C — Credit Cards. Good tool or financial trap — depends entirely on how you use them. Paying your full balance on time means you get 30–55 days of free credit, plus rewards or cash back on spending you’d make anyway. Carrying a balance flips that equation completely. The card starts paying you negative 24% annually. Pick the right card for your actual spending habits, use it like a debit card (only spend what you have), and pay it in full every month.

D — Debt. Not all debt is bad. Bad debt is credit card balances, high-rate personal loans, buy-now-pay-later that carries interest. Good debt is a mortgage at a rate you can service, a student loan that genuinely increases your earning power, or a business loan with a clear return. The question to ask before taking on any debt: does the return on what I’m borrowing for exceed the interest rate? If yes, it can make sense. If no, don’t do it.

E — Earn more, not just spend less. The math of wealth has two levers: income and expenses. Most personal finance advice focuses almost entirely on the expense side, but there’s a ceiling to how much you can cut. There’s no ceiling on how much you can earn. Skills, side income, career advancement — these compound over a lifetime just like investments do.

F — Family and Friends. This should be the foundation, not the afterthought. I’ve seen people make financially optimal decisions that wrecked their relationships, and people make financially suboptimal decisions that built something worth having. Money should enable the life you want — not replace it. Keep that in mind when you’re optimizing every last dollar.

G — Give. When you’re in a financially stable position, give something back — whether that’s to a charity, a community organization, or someone in your life who needs it. I’ve found generosity doesn’t actually cost as much as it seems, and the compounding returns on goodwill are real. The one exception I’d make: tipping should be proportionate to service actually rendered, not social pressure.

H — Habit, not hustle. The people I’ve seen build the most wealth aren’t the ones working 80-hour weeks and making dramatic financial moves. They’re the ones who set up automatic contributions to their 401k and Roth IRA, never touched them during downturns, and showed up consistently for 20 or 30 years. Compound growth does the heavy lifting if you just get out of its way.

I — Investing. To get financially free you have to make your money work for you — you can’t get there on salary alone. You’re probably already investing if you have a 401k or IRA, even if you don’t think of it that way. The key is understanding what your money is actually doing in those accounts. A target-date fund or low-cost index fund portfolio is a better starting point than most people assume.

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J — Just start. Procrastination is the biggest wealth destroyer I know of — more than bad stock picks, more than overspending. Every month you don’t start investing is a month of compound growth you don’t get back. Break it down to one small action: open the account today, set up the automatic contribution tomorrow. The rest follows.

K — Keep capturing your employer match. If your employer offers a 401k match and you’re not contributing enough to capture all of it, you’re leaving guaranteed 100% returns on the table. I’ve said it before and I’ll keep saying it: there is no better risk-free return available anywhere. The 2026 employee 401k contribution limit is $24,500 — or $32,500 if you’re 50 or older.

L — Long-term thinking. Short-term trading rarely works for people who do it part-time. The most tax-efficient path to wealth for most people is retirement accounts — 401k, Roth IRA, Traditional IRA — held consistently over decades. Selling during every downturn and buying back after the recovery is the single most reliable way to underperform.

M — Match your funds to your costs. As my portfolio has grown, I’ve leaned more heavily on index funds and ETFs rather than picking individual stocks. The evidence is clear: most actively managed funds don’t beat their benchmark index over a 10-year period, after fees. Vanguard and Fidelity still offer the lowest-cost options I’m aware of. Minimizing the 3-fund portfolio approach — US stocks, international stocks, bonds — is hard to improve on for most long-term investors.

N — No unnecessary fees. Fees compound against you the same way returns compound for you. A 1% annual management fee on a $500,000 portfolio costs you $5,000 per year — money that would have been compounding in your account. Demand low-fee options on your savings account, your investment accounts, and your credit cards. The cumulative impact over 20–30 years is substantial.

O — Overconfidence is expensive. This applies most obviously to trading options or individual stocks, but it shows up everywhere in personal finance — skipping insurance because you think nothing bad will happen, assuming real estate only goes up, taking on debt for a business idea without stress-testing the downside. Confidence is good. Overconfidence is the precursor to most financial disasters I’ve seen.

P — Plan. Goals without a plan are just wishes. I’m a believer in having a written financial plan — even a simple one — with specific targets for retirement savings rate, debt payoff timeline, and emergency fund size. When you have the plan written down, day-to-day decisions become easier because you have something to check yourself against.

Q — Quit losers. One of the hardest things in investing is selling a position that’s down, especially one you believed in. But holding a loser “hoping” it recovers while better opportunities sit elsewhere is a real cost. Under US tax law, up to $3,000 in net capital losses per year can offset ordinary income, and additional losses carry forward. Cutting a losing position isn’t failure — it’s discipline.

R — Research before you commit. Before any significant financial decision — investment, loan, insurance product — read what experts say and then form your own view. If you can’t explain to someone else what you’re investing in and why, that’s a signal you don’t understand it well enough to own it yet.

S — Spend less than you earn. This is the whole game, condensed. Everything else on this list is commentary. If you earn $80,000 and spend $75,000, you have $5,000 to deploy. If you earn $80,000 and spend $85,000, no amount of investment skill digs you out. The gap between what you earn and what you spend is the only raw material for building wealth.

T — Taxes matter as much as returns. It’s not what you earn, it’s what you keep. A 401k and Roth IRA give you the most powerful legal tax advantages available to most people. Beyond that, understand how tax brackets actually work (marginal, not flat), know your capital gains holding periods, and consider an HSA if you’re on a high-deductible health plan — it’s the only triple-tax-advantaged account that exists.

U — Understand what you’re signing. Adjustable-rate mortgages with teaser rates, variable-rate student loans, subscription contracts with automatic renewals — these trap people specifically because they don’t read the fine print. Whatever you’re committing to financially, understand the worst-case scenario before signing.

V — Value your time correctly. Your earning power is your most valuable financial asset, especially early in your career. Every dollar of skills, education, or networking that increases your hourly rate compounds for decades. Don’t optimize your investment portfolio down to the last basis point while neglecting the much larger lever of your own income growth.

W — Watch for lifestyle creep. The biggest threat to wealth accumulation isn’t a stock market crash — it’s raising your spending every time your income rises. When you get a raise, I’d try to redirect at least half of it before you adjust to the new take-home. The spending level you were comfortable with before the raise is still fine. The extra goes to work for you.

X — X out bad financial habits before they compound. Small bad habits are expensive at scale. A $6 daily coffee habit is $2,190/year. A gym membership you don’t use is a subscription you’re paying for nothing. More seriously: carrying any credit card balance, missing retirement contributions to fund lifestyle spending, or avoiding looking at your net worth because the number is uncomfortable. None of these are fatal individually. All of them compound. The fix is awareness — run an annual audit of recurring expenses and honestly assess what’s worth keeping.

Y — Yes to professional help when it’s worth it. You don’t have to be the expert at everything. A fee-only financial advisor (one who doesn’t earn commissions) can be worth their cost during complicated life events: a large inheritance, a divorce, the years just before retirement. A good accountant often saves more than they cost. Use your time on the things where your judgment adds the most value, and delegate the rest.

Z — Zero tolerance for overdue credit card balances. Pay on time, in full, every month — or don’t use credit cards at all. The people who treat a credit card like a debit card (spend only what they have, pay the full statement balance monthly) capture all the benefits. Everyone else subsidizes those rewards through interest charges. The credit card companies built their entire business model on the assumption that enough cardholders won’t pay in full. Don’t be part of that math.

I revisit this list every couple of years. The letters don’t change — the context around each one does. If you want to know when I update key figures on this page, subscribe here.

Related reading:

• Master Your Money: The Ultimate Personal Income and Spending Roadmap
• The Power of Compounding: $1 Million Now or a Penny Doubled for 30 Days?
• 2026–2027 Roth IRA and Traditional IRA Contribution and Income Limits