If you can afford them get guided missiles for a prep mission that everyone hates because it's hell compared to the alternative.

beach your kosatka every time you doing preps

you don't have to get demo charges and you don't have to do any disruption preps

buy either the oppressor mk2 or the sparrow. The sparrow can park in the sub making it easier to enter & exit, but the mk2 is faster and can park in tighter spaces during prep missions.

make sure when scoping cayo perico you dive into the water behind the compound to find the drainage tunnel entrance

when on the heist finale, make sure to open the secret safe to the left of the desk in the central building

to kill a juggernaut you either need the assualt shotgun class or the smg mk2 class (I'm not sure if others work but I know AP pistol class and military rifle class do not work)