Sorry to bring it up again but anal sex.

Hello lady's I'm new here and I have been looking for some info on how you started having anal sex.. My husband wants to do it and so do I but I want to make sure we do it correctly so it's pleasurable for both of us! Like what did you do your first time to prepare for it? I'll admit I'm scared of a "mess" because from what I read that could happen.. any advice would be greatly appreciated! :)