As a top, I’ve been able to achieve this with two bottoms. The first would only cum hands-free, and only in missionary—and as boring as missionary every night may sound to you, it was unbelievably hot to me, and transformed me from 50/50 vers to nearly total top over a few months’ fling.
If you can find your bottom's prostate that's the ticket. If you know how to grind your dick on it right you can make your bottom cum hands free everytime
With the second guy, I was only able to make it happen once, and that when standing up, my hands on his back with his legs over my elbows, bouncing him down on my cock, and I don’t know who triggered whom; we came at the same time.
It was also his first time getting fucked like that, and his first time wearing a cock ring (borrowed from me), and I think the altogether wow of it tipped him over the edge: it was his first time cumming hands-free. These circumstances I’m unlikely to relive with other bottoms.
Missionary is the best position for us, it may sound boring but it gets the job done, I love it when he pounds my prostate from that position I cum uncontrollably. Also maybe trying bottoming for a really great top.