It is interesting and highly instructive to try some variations.
For example, there is a distinct difference between consciously relaxing all muscles upon exhaling, and not doing so. Can you feel it?
It makes a difference when you flap your pelvis back upon inhaling, and forward at exhaling.
It feels different when you stroke very softly, or rather strong. It feels different to stroke your penis at the tip of its head, or at the root where it meets with the rest of the body.
I don't advocate either of those options. I advocate experimenting, solo or in pairs or... whatever, folks.
What I DO advocate, definitely, is this:
Do not forget to relax at some point.
It happens to me, a lot of the time. I guess it has to do with being focused on some kind of result or success. And I have the distinct impression that most of the time, the real work happens in relaxation more than under stress.
Also relevant: Yaaaay, 50th posting! :-)