>>717800981
simply just play them
But if you want more specifics, it helps if you just stick to one fighter a day. Like play a little SF6 today, a little Strive tommorrow, a little KOFXV the day after then CotW before repeating. You're not going to forget how to play a fighter if you haven't played it for a couple of days and the downtime before picking one up again will allow your brain to kind of reset so that you don't end up having a situation where you play KOFXV then CotW immediately after and then try to activate Max Mode in CotW because muscle memory is still lingering.

That's what I do anyways.