Tips on pressure fighters?

agreed, jab is most important. use it long and vary the placement. the short man needs to get under/inside your jab to score on you so place that jab randomly all over his scoring target (chest, shoulders, throat, forehead, jaw). throw it at his left wrist, throw it at his right wrist. when he's on an unpredictable defense, he's not on offense, and when you're throwing at his body he has to work harder to get in and under. (if he starts to use counters against your jab, then you start mixing fients in there to draw his counter, and you counter his counter) (years ago we had a boxer that was getting their ass whooped by a pressure fighter. they kept on throwing at the opponent's chest and landing on the shoulder. the opponent's shoulder got dislocated and they had to retire. it was a hard fight but we came away with the win. remember there's more than one way to win an amateur boxing match. it's not just on points)

use that unpredictable jab to set up well placed, scoring straight power shots.

using that jab and working circles. he wants to use his forward momentum. don't let him get set. keep him off balance.

diffuse his combinations early. if he's trying to get off a 20 piece it's your job to slip/counter and use defensive footwork against his first or second punch. when you're not there he won't get off the other 18 shots. use drills that practice slip counters + angles, and parry n go + angles (notice how "angles" is common). make him miss, make him pay, and don't be there.

and lastly, don't worry about looking pretty. it may get ugly. i'm assuming you're talking about amateur boxing so all you have to do is score the white of your glove on his target with body force behind the blow. if you end up looking like you're in the matrix, that's alright.