Simplest technique bar none:
FEET FIRST, SAIL AFTER.
That means switch your feet first and then flip the sail whenever you want, but always do it after the foot change.
Works great for non planing jibes. *Almost foolproof*.
You can actually carve through a planing jibe switch your feet and exit the jibe without flipping the sail. It's called "clew first" sailing, practice it and you won't have many reasons to bail/ fail on a jibe.
Secondly: Be well powered. Don't go out with a sail size that makes you "work". Power will always help you jibe, better to have a little too much than too little. Even if that means your sail is too big to duck jibe,ect.
Really the jibe should be the easiest maneuver in windsurfing, easier than short board tacking ect, ect. There's just no standardized way of teaching it and there's a lot of stuff going on at the same time.
Just practice and you'll find that an early foot change followed by a timely sail flip will put the WIN in your windsurfing.
Look for the vids "Guy Crib Intuition" and "Beginner to Winner" on youtube.
ride on brotha