How is the Falco vs Puff match up? I am old school and they weren't beast Puffs back in the day, so no clue how Falco will deal with one.
HOLLA
you should watch some pp vs hbox, like their exhibition sets at tipped off 7 for example
this is the match up I've played most so here's some advice I have:
if the puff is spamming bair, then you have to laser a good deal (laser no matter what, but lasers become especially important because it turns a puff who's trying to bair around and will throw off their rhythm)
dair, bair, and utilt are your friends---you can't get away with too much nair unless you're in their face and they're not dealing with it well or you're managing to laser just right as you approach
dtilt kills in the high 80's, and utilt around 110, upthrow to bair or uair is also a good killing option if they don't di the throw correctly
after low percents, mostly look for dair to dair to dair... followups because puff's techroll is pretty bad anyways
do your best to stay in the middle of the stage-->if you're ever off to the side, you can use fh or even dj (puff is a lot slower vertically than you) to retreat to the middle platform. puff is weird in that she's actually a character that it's ok to be above
be wary of puffs who just throw out aerials and wait for you to run into a bair, or who come off of platforms down to the ground with nairs and such that cut off a lot of space. laser them, get on their height level or directly above or below and wait for the right moment to jump at them.
oh and di their uthrow and shine off the top (yoshis, stadium, rc, especially) when possible
Edit: I'm scrubbish so take my advice with a grain of salt