Spend lots of time on your hands. Prehab, joint prep, mobility work to open the shoulders. Chest to wall handstand holds with the wrists very close to the wall(within a few inches at most). Frogstands help as well. Again, spends lots of time on your hands. There is no substitute for time on your hands. In the beginning 4-5 sets of 10-20s holds with 60s rest will be plenty. As your joint prep and strength increases, you can play with more volume/intensity.