I'm sure there are MANY pieces of advice out there, but anyway..
Do you use your whole palm or just one or two fingers for the hold before the slack?
I've been using my whole palm, and can land it about 1/2 the time. One finger pinch is worse, much.
I'm doing something wrong, and keep avoiding this trick due to my inconsistency with it. I've been yoyoing quite a while and this trick has given me trouble
Tricks that require neutral tension are tedious when you miss them. This is a particular trick where one on one with someone who's good at slack and whip tricks would bring benefit.
Anything open a door for you?