Talk to member eswol, he has used IGF-1 lr3 pre contest for every one of his last few shows, and has it dialed in pretty good if you decide to go that route, he swears by it,
Bring bands with you, they do work, and keep an eye on them back stage, shit has a way of geting up and walking away, like ur tanner, and lotions, especially if you look good! people will fuck with ya, no BS!
But bring bands and make sure you know how long until your going on, ask repeatedly, keep an eye on the guy backstage listing who goes on next as they fuck up and somtimes get it wrong, and you dont wanna go out there without pumping up, now with that said, do NOT pump up too much, you will lose your lines! Just get a nice mild pump so your still able to flex and make the muscles jump when you flex.
I used carbo force back stage, it worked well for me, and i didnt spill over, now i have never done physique show only bodybuilding shows, but its likely all the same in terms of timing your pump, what to drink or eat to fill the muscles with glycogen, and what to bring like bands, lotions etc..
Just remember most importantly, dont over pump! You will spill over water from muscle to subq, and you dont wanna have the kind of gym pump where you cant bounce your tits and flex your arms, You want to keep the pump just under that!