My journey was:

1) side sleep - didn't work after a while

2) cpap with giant over-the-nose mask - I couldn't stand it and I rejected it

3) a boil-and-bite mouthguard to keep my jaw in place and not sliding back - didn't work after a while

4) same cpap as #2, but with nasal pillows - has worked since then

by the way, I had to really learn to breathe through my nose for #4. I guess I didn't always do that, especially with allergies.

losing weight, exercise - good for me, but didn't solve it

this worked for me for a while but in the last year, I've started getting episodes even though I've taught myself to sleep on my side, breathe through my mouth, keep my airway open by tilting my chin away from my chest, etc.. these kinds of techniques only work so well.