No particular order, just typing shit.
Excuse my grammar.
1) Have a pocket
2) Although you have a pocket it doesnt mean to only heal that one person, heal other people around you and give everyone buffs.
3) Call medic to announce your arrival.
4) Run away when your pocket is failing you, or when you dont feel safe.
5) Never shoot or try to fight unless you absolutely have to. Even then, it should be needle spam as you run towards where you team should be.
6) Contradicting #5, with experience you will learn when its good to use that melee when you need too. But never just charge in. Opportunistic attacking.
7) Pop it dont drop it. Never die with 100% charge, unless you wanna be a scrub like myself.
8) Dont hold ubers for too long, if there are a good amount for friendly's around you, tell them to push up.
9) If your entire team around you died, you are being attacked, and no one is even near to protect you. Just let the person kill you so you can respawn with your team. (again this is something you just need to decide when to do/comes with experience.)
10) When you hit a regular uber charge, flash people (2 or 3) by clicking between them as you push forward. Do not do this with krits or quickfix
My medic set ups
Most maps if i have a great pocket:
Crossbow, Medigun, Amp
Crossbow, Kritz, Amp
Standard:
Syringe gun, Medigun, Ubersaw
Syringe gun, Kritz, Ubersaw
lol dustbowl on red team:
Crossbow, Kritz, Amp
Pocket chrs:
Crossbow, Shitfix, Amp
Pocket stanley:
you dont.