What investment pitfalls should I be on the lookout for?

Don’t invest emotionally. It is better to keep a moderate controlled approach to investing as opposed to constantly chasing the jackpot which can be dangerous.
Don’t trust tips. If you aren’t the head of a large investment firm, by the time a tip reaches you, it is probably too late.
Pay attention to your investments. Stay involved with what your investments are doing, don’t rely solely on others helping you.
Reevaluate. Your financial situation may change over the course of time, be sure that all of your investments are still appropriate.