1) You can lean your doll against a wall. See, it hardly looks like she's touching it. This is one i use the most.
2) Purposely touching the wall.
Or the doll stand. Even though your doll may refuse to use this, it is quite useful.
The doll stand:(
Just don't get your hand in the picture trying to keep her still...
If you need to hold onto her, take a picture of the top half of her, while holding her legs.
Hope this helped!