You can always ask.
Tipping you Laser tech or Medical Aesthetician is proper etiquette however I’m sure youre forgiven if you havent been. 
I don’t think it’s proper laser etiquette, you don’t go to the dentist or doctor and tip them. Only one place I’ve been to asks for tips and it’s because they do waxing as well. They don’t ask for them but their debit machine prompts “add tip?” Of the 3 other clinics I’ve been to none even have that option, it shows your grand total and that’s it. The only way to tip would be to give cash which is pretty awkward since all offices I’ve been to have been very professional or cosmetic surgeons which you wouldn’t tip for. Do you tip for botox as well??
I had many sessions throughout 2010 on various parts of my body and I didn’t tip once; and I must say for what I’m paying, it never occured to me that I should be. Then in November I noticed little “gratuity” envelopes appeared at reception as I was making my next appointment. So at the end of my last treatment before Christmas, I left a card containing a token of my appreciation in it, on the counter after I had finished dressing. My tech called me an hour or so later to thank me and said it was “the best gift ever!” I told her that I appreciate what she is doing/has done for me. I’m happy with my results and she always makes me feel comfortable in a potentially awkward situation. I’ll probably give her another “thank you” when I reach the end of my initial treatments.
That said, if you don’t feel that a monetary tip is necessary, a simple thank you card or note sans cash will still go a long way; it’s more intimate and meaningful than a “thanks” as you pull your pants up. I think we could all agree that what these people are doing for us is often life changing.
Thank you!
Kirk
I copied and pasted my reply to a similar post/question as well.