I have always sent a thank you message. I believe it is much appreciated and some of the ladies have acknowledged it,

My 2 cents. I always send a brief note of thanks and appreciation.  Don’t go on and on and don’t send more than one. Provides are busy, so don’t expect a response, but I think you will find many will appreciate the note and send a thank you back.

I do this all the time and almost every provider response positive. No harm in it.

I like getting them, I think it is a nice gesture. I actually used to send them to new clients but I need to get back into the habit of sending them again! It only gets weird if the "feel feels" are involved. Keep it light, keep it professional. That will keep you on the "will see again" list.  

Not weird!

As a provider I love these messages, I'm happy to know you enjoyed your time. I don't think anyone would ever consider it weird.

Thank you for the responses to my question. Of course everything will be kept professional. I'm not here tp catch feels, just enjoy my time with amazing providers. I also know there are a lot of self important creeps out there and I definitely don't want to risk accidentally putting myself in that category.

I truly appreciate them.  I myself try to send thank you notes after sessions.  I must admit lately, I have been overwhelmed with life and that I have slacked on this, but do feel that my clients know I appreciated them and the like.