Here is a routine that I do 90% of the time, specially if I booked way ahead of time.
2 days before, make sure I trim my balls and also my fingernails.
On the day of I do all my usual stuff in the bathroom early.
Since I live about an hour away from her I text her just as I leave.
If she needs to cancel, I'm usually just 10 minutes away from home so that I can turn around and do something else.
I do have on occasion a backup plan, visit a massage parlour but they usually open 1 hour after I arrive in town.