These are my experiences with 4 girlfriends, over about 7-8 years.
Expressing dominance as in restricting her movements, holding her down or immobilising her.
I start dominance about 3-4 months after first sex.
First time it happened casually and non intentional, while doggy, I grabbed a handful of hair and banged away.
After, gf said she felt I was being very man
When with the next gf, also in doggy, did the same thing deliberately, although was progressive, first hand grabbing shoulder, then neck, then hair.
When I asked her after, she actually blushed and said altho don't know why, she liked it when I did that.
Experimented with her more after, both face down, me on top of her, with my forearm pressing her shoulders down, or across her throat, my other hand pressing down on the side of her face.
The sex became more intense for both of us.
She also became more submissive and said she enjoyed it more.
The next girl, the 3rd girl I tried, did not like it.
I can hold her hands down above her head when in missionary, but the others she did not like.
Did not progress much after.
4th gf liked it, even encouraged me, once asking why I released my hold on her so fast when my hand slipped and choked her neck instead.
We tried measured choked play (I did not like it), and it gave her intense orgasms. Something about being unable to breathe and the sex accelerated and magnified the feel for her.
She also became more submissive and more horny.
Just don't try with paid sex, they don't like their hair messed up 
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I get the feeling that dominance play can improve the sex and also the relationship, as in SG, not really many chance to display dominance in everyday life.
Note, dominance play, not rough play. 4th gf liked rough play from me, I prefer dominance.
Maybe females, to some extent, are willing to be dominated during sex, as they are already exposing their most vulnerable parts to us. And dominance is a display of strength which they want.
I encourage bros to progressively try dominance play with their gfs and share their experience.
And also what are dominance play positions there can be, with no tying up of the girl.
I find tying up of the girl to a fixture limits positioning.
Have tried standing doggy, holding her hands back. But it hurt her shoulder joints and just not as fluid in thrusting.