Cheat Sheet

Pre-Mission Checklist

Gather with others for briefing.
Change your compass to max distance. Ctrl +
Adjust your local speech volume to 3/4. TAB
After briefing, put in earplugs.
Eat and drink before getting equipped.
Follow others - usually to helicopter or vehicle.
Get into vehicle quickly with SPACE or v or mousewheel/select seat/wheel press
Try to follow map whilst en route for general awareness. M

0 (zero) to sling on shoulder. Least fatigue and necessary to use medical skills.
Double Ctrl' to hold weapon pointing down at ground. Polite in friendly company. Uses less fatigue.
1/2/3 usually 1 - brings primary, secondary or tertiary weapon to bear.
Right mouse click to bring sights to eye.
Right mouse hold to zoom slightly

H key - check the casualty is the focus, not you. You can swap in the menu.
If your buddy got shot, somebody shot them. Is it safe for you to go in to rescue? Consider using smoke or winning the firefight first.
Focus on stabilising the casualty and moving them to a safe place. This may mean tourniquets, bandages and CPR, but don't be afraid to pick them up if you're not safe where you are.
Anything past 'lost some blood' will need a medic. Stabilise, provide CPR as required and take your casualty to the medic. Continue CPR while waiting for the medic to get to your casualty.
A 'strong heart beat' is an indication that your casualty may need morphine to stop them entering cardiac arrest. Do not give more than 2 doses of morphine in a short space of time.

Running - it's really hard to tell if you are crouched. Press x to toggle crouch and try not to run crouched as it will eat fatigue.
Crouching or lying prone while stopped will regain stamina faster.
Moving with your sights up will slow you down and eat stamina faster.
If you can't seem to run and have tried everything else, try Ctrl C

Get a buddy and try to stay with them. Ramboing off will get you killed, or your buddy killed. Stay in sight/hearing/radar range of them. This is a team game, not Call of Duty.
Talk to your buddy and get them to talk to you to communicate when you are moving off and where.
If you haven't heard from your buddy in a few minutes, check on them. Especially in vehicles!

Eat and drink when your icons start to show dark yellow/orange and you have a moment.
Check your ammo regularly and tell your squad lead if you start to run short.