You know the smartest things to do with your money. But what are the worst moves? What should you avoid?

Weirdly enough, they are things that a surprising number of people are still doing—even though they probably know, in their heart of hearts, how foolish they really are.

Any list is going to be incomplete. But here are five to avoid.

1. Reaching for yield

What this country needs is a good 5% certificate of deposit. Instead the collapse in interest rates, and the Federal Reserve's policy of keeping them down for as long as possible, is driving people crazy—especially people who need to generate income from their investments.