Lube... LUBE... MORE LUBE...
My ex was really into anal for pregnancy prevention, some bros here might not believe me, but her sister advised her to do only anal to not get pregnant, so lucky for me.
1. She will normally try to clear her bowls way before we meet up for action.
2. When we did foreplay, i will try to relax her as much as possible
3. Slowly finger and stretch her anus
4. Use lube, both on her anus, and your cock
5. Doggy easiest to enter for us
I think someone posted on prepping on anal, but the picture was a cartoon hairy man. LOL