stand close, jump away, perform the fatality motion in the air, and then hit the last button press when you land. You will be jump distance away (about half screen)

Are you talking about Reptile's MKII fatality? I believe "jump distance" in that game is equal to four "full steps" (some characters take full steps with a single joystick tap... I forget which ones but I know Shang does).

A quick way to get four steps away is the jump method MK2B described. Also I believe an uppercut will put you four steps away from the opponent. For example, Scorpion's fire fatality is done from three steps away, so if I beat the opponent with an uppercut I take one step forward and then do the fatality. If you're Reptile and you finish with an uppercut, you could hold block when inputting the fatality so you don't step out of that sweet spot. Remember this is all for MKII, I kinda forget how these rules apply for all the games after that.

And if you find it too complicated to do the fatality while in air, just hold block and do the trick, then release.

You don’t need to hold block if you don’t want to, just stand close to the victim, jump away once, and do the fatality where you land.

Im talking about mk:trilogy btw!

We know, the jump thing works for every game.