Jump and aerials related question

[MajinWho?]

I see tons of good puff players who will chain together 2 or 3 bairs at a time, but for some reason it seems like unless I start with a double jump, I cant get more than one Bair to a jump before I touch the ground. Or, I'll see players set up rests on fastfallers by up-throwing them onto a platform, jump, up air, jump again, and rest- without hitting the ground. When i try, I always hit the ground after up air, even if I do a full hop. Is my timing just trash or is there some basic tech I'm missing?

 

[The Prince: SDJ]

SH Bair to air jump is a 2 frame window
have to get out the bair within 2 frames of jumping off ground
have to jump asap after bair ends
cannot fast fall

 

[MajinWho?]

SH Bair to air jump is a 2 frame window
have to get out the bair within 2 frames of jumping off ground
have to jump asap after bair ends
cannot fast fall

Gotcha, thanks man! I tend to fast fall out of habit, so that might be the issue.