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
7. Collect dust and pay high fees on it
8. Leave coins in an exchange
9. Trust the wrong people and get scammed
10. Panic at a price correction
I've done 4, 6, 7, 8, and 10. I also did "Panic Buy" which is not on the list. What I mean is buy after the price jumps up because you think you are going to miss out, then the price drops.
I'm sure most of us have made a lot of mistakes in the past. The best thing is to learn from them and try to make the best of it going forward. And you can still make a profit even if you lose money on mistakes as long as you keep working on it.
The panic buy is a pain in the ass I've definitely fallen for it once or twice. Always tends to be okay in the long run though. Number 4 and 10 are definitely the two that have gotten me.