1- If your chart just "mewned" never buy in green, yes it could keep going but if it has already just shot up without any meaningful pullback you increase your risk and have already missed out a portion of the reward so don't run after scraps.

2- If your asset just dumped 50%+ do not sell in red, it's already lost half it's worth the possibility of it dropping more is possible but when you at the bottom there's nowhere to go but up, buy the fear sell the greed

3-do not use leverage until you can you know what you are doing, this means a few weeks of consistent winning calls, yes there will be a few wrong ones but if your wins outweigh your losses losing some money occasionally becomes a fun part of the process(you also NEED to know how to manage your risk accordingly)

4-NEVER GO ALL IN

5-NEVERUSE WHAT YOU CANNOT AFFORD TO LOSE, the market can do anything at anytime 

6- All markets have ups and downs more often than not the patient person will always win since over an extended time basic inflation will make most assets grow in value where as holding fiat,y purchasing power is always on a downtrend

7- If your in a position that just shot up 100%(as a example) don't be afraid to take some profit you earned it maybe let some ride if you think there's potential but treat yourself this could end at any second

99- I will add more to the list in time feel free to give suggestions in the comment section I'm trying to make this as simple as possible for new people to understand what they should be prepared for. Thanks for reading hope your gains are big and losses become a funny memory.