My T and I use touch copiously and it came on gradually. We have never discussed boundaries I'm guessing since my T doesn't seem to have many and/or we haven't had an Issue.
I don't get anything I can't straight come out and ask for so it started with post session hugs. Then we moved on to body/energy work--- so she does work on freeing up energy in my body which is sort of like a very gentle massage.
As we started doing more inner child work we added snuggling at the end of my sessions. So at about 15,minutes left she will sit on the floor . I put my head in her lap and she rubs/scratches my back and neck. Sometimes we use this time to talk about sensitive issues in our relationship. Sometimes she uses it to tell Mr how much I'm loved. Then usually I'll snuggle into her side and she holds me for a few minutes. Also Im super ticklish and LOVE being tickled so there is usually some tickling thrown in there somewhere. If I really feel sad about leaving I'll hold on and refuse to.let go and then she will tickle me til I let go which takes the sting out of having to leave.

For me there hasn't been a negative side. I had a rely neglectful and abusive childhood and the loving touch is teaching me to take in nourishment, to accept love, and to learn how to love and comfort myself when I alone.

I've been with my T for 4,years. We've been doing the touch for 2. Its been transforming for me