You obviously can't avoid to be banned. It is a race between pokefarmer vs their defense It is impossible for them to see if you are regular user or not, however, they can track your routes and try to detect some impossibilities like walking over buildings, over rivers, etc... Try to find a park where you have a lot of moving place without obstacles, river paths etc. I just got banned on 2 of my accounts both level 30. Try to use common sense. Take pauses, check time zones if you're going in different time zones... (no1 will be seeking pokemons in central park in 3 am) DO exactly same thing that you are doing while playing legit gl!
Thx! I think niantic did great job on GPS player... I made two ID more.. and it has banned in one week again. I'm losing interesting this game