Really depends on the class you are playing and its not just your player character but how you build your companions up as well and they should compliment your player character. Range is important in the game and so is light, so if you have characters that cant see in the dark(humans giths) then be sure to have a dancing light cantrip. Try to get the high ground and hide before a battle, positioning is important for melee characters, dip your weapons in fire or poison. What weapon you can use will depend on your strength or dex. Str based characters can use heavy weapons, dex based finesse weapons. I once ran with a mage with very low intelligence knowing that I will be getting a helm that gives me 18int. Suggest you watch some build guilds on youtube as well, plenty of those around.
