Be very skeptical of anything that promises high returns with no risk. If it sounds too good to be true, it is. The dot-com bust should have taught everyone that lesson. Slow and boring index funds beat hot stock tips over the long run.

I made this exact mistake when I was younger and it cost me. Learn from others instead of learning the hard way. The personal finance section of any bookstore has dozens of books — they mostly say the same sensible things for a reason.

Taxes are the part everyone forgets about. Whatever you're planning, factor in what you'll owe Uncle Sam. Talk to an accountant — a good one saves you more than they charge. H&R Block is fine for simple stuff but get a real CPA if it's complicated.

The simplest advice I ever got was: spend less than you earn and invest the difference. Sounds obvious but most Americans don't do it. Track every dollar you spend for a month — you'll be shocked where your money goes.