1) Hygiene, wash up before the appointment or just as you get there if you go directly from work
2) Get a Hobby phone
3) Do your research.....read reviews, send PM's etc.
4) get a hobby phone.
If she says she's reference friendly make sure you get her phone number so you can put it on your resume.
If she has a shared incall be sure you introduce yourself to all her roomies, it's just polite.
If you forgot an ice breaker like flowers, just pick some from her yard or flower pots on the porch. If she thought they were pretty enough to plant then she must like them and you can get brownie points for giving her some of her favorites.
The night before, be sure to eat a meat heavy meal with lots of garlic and onions. Double up on the asparagus. This is especially important if she's BBBJNQNS.