I really enjoyed watching this video: 10 Things I Wish I Knew When I Started Microsoldering. The ten things are:

1. You can only learn by actually working on motherboards
2. You can actually get good quality tools (for cheap) from AliExpress
3. Just because a tool works well for someone else doesn’t mean it will work well for you
4. 90% of good soldering comes from having an understanding how heat works and how heat dissipates
5. All the pros that you see on YouTube are still learning too!
6. Know your limits, there are some problems you can’t fix
7. Some things aren’t worth fixing because of the time and effort and cost involved, but sometimes things are worth fixing just for practice and learning purposes
8. BGA work isn’t as scary as it seems or is made out to be
9. Buy your consumables in bulk
10. Spend time learning from pros on YouTube!