Honestly the best thing I could suggest is to talk beforehand about stuff that isn't tickle related. It makes it a lot more fun if you have some kind of rapport established with your partner before you do an actual session sort of thing.
One of my friends who's also a 'lee and I have a tradition, we watch a really shitty movie beforehand. Just like, something godawful. Then we kinda joke about it before/during/after the actual session, and that's usually a lot of fun and adds more dimension to it.