Baalz wrote a
Guide to Thugging, you should check it out.
Mostly it is a matter of what troops you are using to thug.
Bane Lords are immune to poison and have fairly high natural protection, sticking them with a Snake Bladder Stick, ring of fire/lightning protection, a good Shield and a pair of winged boots should get you pretty far as a raider or general nusiance.
Still, gear your thugs primarily after what your enemy is bringing against you.