From the post, here are the descriptions on how to preform the techs. If one of them is unclear, I'll try to explain it further.
- Turn-b: Shifts direction but not momentum. Preformed by tilting or tapping the analog stick backwards and then doing the input for the special. (or for side b, just hit back and b.)
- B-reverse: Shifts both momentum and direction. Preformed by imputing the special normally, and then, very quickly, tapping the analog backwards.
- Wave Bouncing: This tech is a combination of both of the above, and it shifts momentum, but not direction. This is preformed by first turn-bing a special, and then immediately tapping forward. For instance, to input a wavebounced side-special, you would hit back and b, then immediately tap forwards. For a wavebounced neutral special, you would tilt the stick back slightly, then hit b and tap forward.
As for the uses, each and every tech is useful for all of ZSS moves, save for down-b and wavebounce and turn-b on up-b (at least, very limited use).
Turn-b: Very useful for blaster and plasma whip. Mostly used for retreating specials. Let's say you poke at their shield with bair, then run away and do a turn-b blaster or plasma whip etc. It's also useful for just doing blaster out of dash dance or the air or whatever, if you are facing away from your target. For down-b, let's say you are comboing someone and they DI up and in, but are just out of double jump range. You can do a turn-b flip jump, then double jump cancel into a bair to secure a kill. (at least, I'm pretty sure you can.) For up-b, I have not found a use.
B-reverse: For plasma whip, it's useful for a retreat mixup. Let's say you hit their shield with something and start running. When you shorthop from out of your side-b range, they may do something like start up a projectile. You can then b-reverse to land a side-b on them when they aren't expecting it. Not very useful for blaster, but you can use it similarly to plasma whip (though it just seems kinda worse.) Also, if you want to side-b or blaster backwards out of run, you need to b-reverse it. For up-b, it's mostly used for recovery. If you wall jump, you can up-b boost the jump and b-reverse the up-b to shift the momentum towards stage, allowing you to land on stage. You can also use it to end combos. Say you are going REALLY deep to land a double jump up-b off stage. If you did it normally, you wouldn't be able to recover, but if you went a little bit past them and b-reversed it, it might give you the ability to make it back. It can also be used off ledge. If you drop ledge, double jump backwards, you can b-reverse up-b and then grab ledge again during the animation of up-b.
Wavebounce: The most difficult and fun. It's useful for both blaster and side-b. There's a mixup with regular and wavebounced side-b, where you just towards them and side-b. Aim for where they are standing. They will often run at you and hit you out of plasma whip, but if you wave bounce it, they'll hit thin air and then get nailed by side-b. wavebounce blaster is similar, but less useful overall. Mostly just a movement option. Haven't found a use for wavebounce up-b that b-reverse wouldn't do just as well, and I don't think wavebouncing down-b does anything.
As for what these all look like, turn-b will just turn you around, b-reverse will completely reverse your momentum and turn you around, wavebouncing will completely reverse your momentum, but won't turn you around.
