Speed and Mining
You should always be aiming to go quickly, and push forwards or complete the objective. This is most notable in point extract, where slow teams can get stuck killing enemies and not progressing. This can mean ignoring enemies or hard to reach minerals and focusing on the objective. Not every cave needs to be fully explored or every enemy killed.
Make sure to use your equipment liberally. In a four man team you will have equipment spare so using it to get around quickly is ideal. In a worst case scenario everyone can fallback on the driller. On higher hazards the bigger concern is ammo and health, rather than equipment.
When choosing a spot to hold, having a chokepoint can be a great way to be efficient when killing a swarm. Dirt walls always make for good hold, however be ready to kite if the choke goes wrong. Explosives like detpacks are useful for dealing with armoured mobs like praetorians and scout’s IFGs can make a massive impact.
Having a good area to kite in can be critical if your team gets into a bad situation.
While going through a cave it’s always a good idea to keep a mental note of where you came from. In complex caves you can mark the wall with your pickaxe. On gamemodes where you have to run to the pod, having a path back can be critical, especially on short missions. Ziplines are a great way of doing this. If you have a driller, he can drill back to the pod for an easy escape, but make sure to stay close and cover his back.