Field battles:
Always take a board shield if available + allowed
Use it like you're a 1h.
Once there's a melee switch to yor 2h and use thrusts/overheads to kill, preferrably against enemies your friendlies are alreadt fighting.
They have many shielders? Use a great axe/bardiche. They're usually available.
Dont be too eager for kills - this gets you shot, stabbed and raged on by friendlies whom you just tk'd.
Stay in cover.
If you have no pts in shield, dont stand in shield wall bcos Sod's Law means your shield will take 90% of all incoming arrows and as you are the weakest shielder there, it will break first. This nearly guarantees a death with no opportunity to kill cos u cant pick up shields with no shield skill.
Apart from that, try different approaches/areas of the map to fight in and see what works best.
Sticking behind a 1h and thrusting the guys spamming him is good.
For Sieges:
Attacker
- dont go solo up defended ladders
- use a shield, sometimes even when you get off the ladder, so your teammates can start fighting the enemy. As soon as they stop attacking you, go mental and kill as many as u can
Defender
- dont crowd 1 spot
- morningstar is always better than great maul
- take a sniper if allowed or bolts and loot the sniper (not sure how 0 wpf accuracy is affected post-patch)