3 investing traps and how to avoid them

Alcoholics have 12 steps. Grievers have five stages. Investors have their phases, too, with the biggest leap coming when a fledgling shareholder begins tossing accounting ratios around. I've calculated ratios for years myself, both as a hedge-fund analyst and in making share recommendations for The Motley Fool, and I'll say this: ratios are both powerful and open to misuse by novices. I'd like to share a few tricks with you to help you avoid some common pitfalls.