As she begins to lick and suck on your finger, copy that motion exactly on to her pussy. I think everything in this post is excellent advice as long as everyone understands its not for everyone. You can take her level of excitement and kink to even another level by handcuffing her to the bed. You may guide this path with small kisses from their neck down to their pelvic region. The most common and one that I have described these techniques from is with her lying on her back with knees bent and you sitting or lying by her legs.
Activation in progress
Get your middle finger wet in her pussy for a few minutes and make sure you go in and out, and when going out, bring that wetness down to her ass hole. My woman wants a suck on her but it gets me irritated doing so… How do I start, judging from other smelly past experience with girls.