Ive been bg botting around 20h everyday, 60-70% AFK, I started at level 80 after using Kicks guide, also 60-70% afk.
The best tip I can give is to keep your gear up to date. I intensionally make my DK to farm heirlooms for my future alts, me and a couple of friends are rerolling. However, when I hit 85 with my Wotlk greens/blue everyone raged and bashed me, thank god I wasnt afk.
Bot smart and good luck!