Nail these movements before trying any higher level work(back lever, planche, one arm chin up, etc.):
Muscle up- slow and controlled in all phases of the movement, even the transition
Lsit- 30 to 60 second hold on the floor a la Coach Sommer
German hang/skin the cat- work up to a 60 second hold in one set. Follow Coach Sommer's protocol for training(50% of max set length for worksets to aggregate to 60 total seconds). This prepares you for the back lever
You may also want to work on these:
Glute ham raise/Harop Curl, Pistol squat, the Shrimp(Ido Portal), Ring dips, russian dips, korean dips, etc.
Prehab is crucial. Coach Sommer's wrist routine, external rotator work, trap 3 lifts, wall extensions, Ido Portal's Scapula and Shoulder routines etc. are all very useful tools to keep you making progress.
Check out the gymnastic bodies forum. Lots of good info there