ok here goes...
1.) Get her drunk or at least a lil tipsy. Always more relaxed with alcohol in your system
2.) Get her extremely horny...lots of foreplay (women love foreplay)
3.) doggy style position with head her up close to the headboard to keep her from jumping and your cock coming out..
3.) SLOWWWWWLLLLLYYYYYY insert cock into ass! Notice how I stressed the slowwwwlllyyyy part.
4.) Do not ram it yet! Go slow in and out but make sure you don't pull too far out cause it hurts like hell the first few times. OUCH!!!
5.) Use lots of LUBE!! Dry fucking the ass also hurts like hell.
6.) When and if she really gets into it....then you ram it, just take your time with that part though. Get her to masturbate while you are fucking her...That really does feel good