I know this is a bit late but while agree Read the Rules.
If your Looking at a "MilsimIV" rule like at Millsim west Carry 4 Liters of water every time you play in addition of all the gear you normally play with. Slick every thing you carry While some argue against Plate carriers/helmets Read the rules some events are working armor into them as part of the rules set IF they do that and every one else in your squads rocking plates you'll stand out Which is a bad thing FYI Even if helmets have no game value... Protect your grapefruit!!!
Check the Rules on Moving wounded players IF you can move a casualty Then set up a Triage And move casualty's to you when ever possible.
spend some time getting used to Quickly bandaging people as for weapons avoid looking like the medic and If some ones yelling out wheres the medic Don't wave your arms

all-way's assume there's a sniper out there somewhere.