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
6. Waste time on faucets (we all did)
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
11. Do not educate yourself
12. Do not read references about services
13. Leave coins on the mining pools
14. Transfer a large number of bitcoins
15. Do not CHECK twice or 3 times where you transact!!
16. Do not read the profile of ICO or a investing assets.
17. Tell everyone you have bitcoins
What a useful thread. A reminder for everyone, not only newbies.