Great advice from Ms. Pleiades and many others. Play what you like, and try to have many helpful items, including a healing wand. Unfortunately, there are no potions of see invisibility, because it is a personal spell, but it is a great scroll to have.
Ms. Pleiades wrote:
Just be sure your character has alchemist's fire, acid flasks, holy water, rope, a healing wand for themselves or others to use, smoked goggles, potions to revive the wand user if they go unconscious, antitoxins, antiplagues, light sources, oils of magic/bless weapon and later on potions or scrolls of see invisibility.
Lastly, Trollbill is correct, buffers are awesome for always having something to do. Either bard or witch (with the hexes) work particularly well, although buff-focused oracles are good too.