Method of learing IB - punishment

[Flick]

As a potemkin player, i realized that IB is essential to leveling up on my way with him. But i haven't found a effective way of training it. I try start with record some easy-to-see move like Sol's BB, or Slayer's Mappa ... etc, and some basic Ky's blockstring ( In order to improve my reaction, too ). But after about 2 weeks of hell training, i still sucks @@, still eating these move, or successfull in IBing, but forgot to PB. I wanna ask you what is your method of this kind of training?

Ty all, all will be appreciated