This is how I land:
While flipping and/or twisting, I would curl myself into a shape of a ball so I'll be flipping/twisting faster, I will have to watch that jump from beginning to the very ending. If I don't seem to land, I will have to do something about it.
I could be gaining to much momentum and I end up hitting my head, to solve that I can either gain more momentum to get that extra flip/twist. Or I can just reduce the momentum be spreading out my body
Watch these example replays.
Take a look at "flipsfail" first, you can see that I didn't stick the landing with 2 flips. It doesn't mean I can never land it because of what you saw, you can go back to the replay and edit it.
Now look at "Flips." I decided to do only one flip, but I can do two if I want (by gaining speed/momentum). I relax all in the air and that made me reduced the momentum of the spin.