I don't use proxy server settings and just stick relatively close to my home area with realistic botting and travel times. I don't let it run at all unattended and I've made it to 31 now without receiving so much as a soft ban, though I'm treading lightly because I've read Niantic likes to keep a close eye the lvl 30+ range. The important thing, IMO, is realism. Use the bot to mimic how you would play IRL.
If I want to bot in an area further from me (within reason, obviously I'm not traveling the globe on a daily basis), I will hit spots between my house and the destination. For example, I live in Tampa, FL and I want to bot in Daytona Beach to get myself a Tauros, I use
The Silph Road to find nests between Tampa and Daytona Beach, stopping at one or two along the way using a realistic driving timeframe. I make the bot look like it's taking a day trip, if you will, instead of just popping up on the other side of the state.
I occasionally adjust the
Move Cycle and
Speed between locations just for variation. Typically I alternate between "Run between Pokestops" and "Run between Pokestops and Gyms", using
Jogging, while only using
Ride a Bike if I would be in my car idling around the area I'm botting in. If it's a beach, use
Walking to make it relative to the terrain, since you walk slower over soft sand. Additionally, I try to avoid areas where it might look like the bot is walking over water or through buildings.
I never have the bot skip any Pokemon or Pokestops. My Pokeball strategy is Pokeball>0, Greatball>450, Ultraball>650. Use random throw accuracy. Use Razzberry if CP>550. I use the
Transfer Immediately option, keeping two of highest IV and protecting all of the final forms in a Pokemon's evolutionary chain from being transferred so that I can check their move set beforehand (I.e. Venusaur and Raichu can't evolve again, so they're protected. Onix, Magmar, etc. that have no evolution (yet) are also protected.).
Lastly is to ocassionally spend some candy/stardust to evolve/powerup a good Pokemon and hit a couple gyms on your personal device from time to time!