Alright, I'm gonna give you advice I wish I had been given. I've gotten two six month bans and one permanent ban.
#1. They don't monitor IP like goat said, they also don't monitor entire accounts. Like your whole battle.net email, you can make another fresh account on the same email that had a perma banned account and you start as if you're a fresh greenie with a perfectly spot free record, and no monitoring at all.
#2. AFK Botting -will- get you banned. Not immediately, but eventually it will. 100% guarantee. I do bot and let the bot take control of menial things like apexis farming or leveling, but I -never- leave my computer completely unattended while I do it. I'm always at the house to check on it just in case. I only let the bot take movement control maybe a total of three hours every week. So I'm pretty safe* there, in terms of ban risk.
#3. Combat routines usage. Now, I DO use combat routines, but I always hold the steering wheel. I'm always in control of movement, but I let high quality combat routines do most fighting for me in terms of rotations. That as well is pretty safe*. I survived the last two ban waves with it.
#4. Questbot. Now questing is tricky. What Blizzard monitors a looot for botting is repetitive actions, especially over a long period of time, say 2-3 hours straight. They start noticing when you're travelling basically the exact same path over and over and over for a very long time, following the same basic coordinates, always ending up at the same place pretty much the same way. Don't do it often if you can avoid it.
#5. Gold farming. Don't. Just don't. Buy gold from a credible website or find a seller on here or somewhere else credible. Never gold farm on an account you aren't prepared to lose. You WILL get banned. 100%. Do not buy gold with RL money over the amount of 60-100k. NEVER use the auction house for large gold transfers. You'll get caught. 100%. The auction house is VERY tightly monitored.
#6. The usage of the word safe* in this post. Nothing is ever safe. Even following the safest* possible method, like me, you can still get banned permanently. There will always be a chance. It's just how low or high your chance is depending on your botting patterns and habits.
Summary: Basically, try to do everything yourself while using Enyo and letting a GOOD combat routine from the store handle the rotations. Still a risk, you can still can caught and banned, but it's WAY lower. Try not to afk from the bot -eeverrrr-.
Happy botting!