1. Do not remember electronic wallet password
2. Do not back up your wallet
3. Do not research new services
4. Buy and sell based on feelings
5. Leave your money in the electronic money floor
As I observed the most common mistakes that we committed is trusting a person whom we dont even know yet.
I agree with this 5 common mistakes specially in the newbie because they are not already know how to deal with it. But things much better you can learn your mistakes and be careful the second time around.