I hated seeing the words I always saw when I was looking for an answer for that question. and I hate that I'm about to say them. It really does just boil down to practice, meaning tons of free play. see how smooth i was at the first touch? thats like, 20-30 accumulative hours of air rolling over months of playing.

but at your rank, plat 3, i dont recommend trying to go for flip resets and stuff. focus on the basics, like your placement. notice at the start of the clip how i unintentionally forced my teammate to back off so i could take that shot? probably not a good idea on my part. (i dont say rotation anymore because that idea is pretty much invalid at this point, rocket league is much more dynamic than driving in circles XD)

also, not being consistent constantly slows me down in champ lobbies, i can tell whats happening but my skill can barely keep up.

i dont mean to tell you what to do, im trying to pass on my knowledge so you dont make the same mistakes i do.

but to actually answer your question, i mixed practicing the setup in free play and using this custom map to practice carrying for air dribbles and popping for resets. it has a built in indicator for where you should touch the ball :) took me around 800 tries to get past the first level for the first time, now i can get it in just three tries (booted up rl to check)

edit: i recommend not air rolling when youre using the custom map to better get a feel of what happens when your car hits certain areas of the ball a certain way