I recently had a client who has explored tantra before so I asked him about it and he explained what he was looking for/wanted to do with me. We started our session taking a shower together, he spent a lot of time just soaping me carefully and slowly, then I did the same to him. Once on the bed, it was a lot of sensual caressing. Much of the focus on me, and for him, it was about keeping him aroused but not letting him climax until the very end. We didn't even have sex, he finished himself off with his hand whilst I stroked his perineum.
Since I've seen him, I've watched a few videos online about lingam massage and also done a little reading about tantra. It's interesting, something I hope to put into practise in the future.