I know a couple of my longest term regulars birthdays and they've gotten free time or a free booking on their birthday. I've gifted or lent a book a couple of times but it was something relevant to a conversation had. Gave one client I had a few overnights with a particular bottle of whiskey that was harder to find for Christmas one year.
I think it's harder to gift as an SP for a couple of reasons.
1. You don't want to encourage EAS and you don't want the client to think you have EAS either.
2. I think it's actually harder to get a gift for a man, especially if what you really have in common is that they want to shag you
. Someone might have been your reg for 2 years but if your conversation is limited to 10 minutes at the end before they leave, you don't have much to go on, while I think it's easier to get women gifts like chocolate, alcohol etc.
3. The fact is, even the clients who say they are single could actually be married or have a girlfriend at home. Noone likes the idea that they might buy a gift and it ends up tossed into a bin on the way home.