This is a problem I'm struggling with at the moment.
I've had a regular for the last 15 months or so and it was great in the sense of each of us learning which of the other's "buttons to push". The downside is if/when it becomes a bit too "cosy".
So, at present, I'm experimenting with some new-to-me girls, all have whom have a respectable amount of feedback on AW of course, and re-visiting one or two whom I used to enjoy seeing before I met my current regular. Btw, I'm still seeing her but not as often.
I must say I'm quite enjoying this experimenting
and have already acquired a new regular, but not frequent enough, Escort through it.