Being emotional. It's hard to control your emotions especially once prices go down and you see all your money go down the drain. The panic seller's attempts to cut losses has only hurt them more in the process and makes them end up losing even more. Unfortunately, FOMO takes over and this is what kills the newbie traders. Using your emotions will probaly lead you to lose everything..
Drifting through the wind. chasing the ones that are already pumping, which is very risky. You bought when the price is still high then price dropped and you are holding a bag of expensive coin.
Don't put all your eggs in one basket. Diversity. Diversify your investments so if one falls, other investment may help you to recover.
For best in the trading field you need these 5 things to be added in your check list, as all these five things are pillars of success here in the trading.
1) Solid Trading Strategy
2) Trade Plan
3) Money Management Skills
4) Reasons for Entries and exits.
5) Journal, News
P.s
I have quote some people words from my last topic
Good analysis. I think you have applied all you experiences on the lists that you have made. I have committed a lot of mistake in trading too. I can still remember the first time I tried trading, I had FOMO and bought coins during the peak and lost almost .05 BTC(it was a big amount for me since I was just a newbie that time.)