Appropriate amount of contact?

... The non-sexual kind. As some of you know, I'm from out of town and visit frequently. I was curious what you think is an appropriate amount of contact pre-TCB with providers. I'm sure it varies but are there some general guidelines I should respect? Enlightened self interest, I would like to make a good impression on the board to help with references so I'm not a complete unknown when I come to your area and I've also sent some pm-s to providers so when I do get in town, they might remember me.

I'm trying to find the balance. I know you all have personal lives and are also TCB with actual near term potential appointments so a pm or email that just says 'hi' may be unwelcome. Any advice is certainly appreciated and for those of you I've met or have communicated with already, thanks for you help and welcome to your forums and city.

Just ask em --- I text regularly with a few ladies but I let them know it was ok to text or call whenever -- and if its someone I enjoyed talking to then I ask if they mind a text from time to time