Rarely.
I mean, I have given small items like a snack, a coffee, etc plenty of times, and had same reciprocated. Actual gifts though, I can only think of 3 girls over 16 or so years.
Girl 1 I was discussing a book with, so on next visit I brought in a copy for her. The next time I saw her we spent most of the massage discussing the book etc as she had read it on every break she got etc. It was a small gift, but greatly appreciated, and she in turn gave me a copy of her favourite book, which I still have. We ended up going out for a while before reality caught up with us both. She's back in Korea now..

Girl 2, I had known for some time, she was the classic story of the girl here earning money to send home to her family. Her birthday was approaching and it was her 30th, she had nothing special planned and didn't buy gifts for herself, had no boyfriend, wasn't the type to ask for gifts etc. So I looked up her birthstone, and remembered she had said how she prefers silver over gold when she saw my rings, and so I bought her a silver bracelet with her birth stone, not expensive, just something to make her feel a little special for that day. Our "relationship" was only ever in shop, never swapped numbers etc, but she was one of the greats. My longest running regular, I guess I saw her for over 3 years. She bought presents for me when she went home, and would often bring me in food during a session when she thought I had lost weight...

Girl 3 I had become a regular, got to know her well, she told me about an issue she had which worried me (perhaps a Superman, or Captain America, complex issue of mine). I wondered whether it was made up, as many stories can be in this game. When I found out it was true I got her something I hoped would help with the situation. It was not long after that I stopped seeing her, so never got to find out if it helped. In my mind I like to believe it has, the things we tell ourselves to make us feel better hey?

Would I do it again? Never say never. It's easy to say all working girls are money hungry vixens who will chew you up and spit you out, but there are always exceptions to the rule.