Hey man, glad to be of help. To your question. I enjoy having extensive foreplay, so usually the girl is so turned on when we get on with sex that she will do anything "vanilla" that I wan't. Also I'm relatively dominant outside the bed and nowadays get girls often tell me that I'm quite aggressive or dominant while in bed. My go to answer there is "And you love it". If I'm changing positions I'm just giving orders to the girl as you said.
There is also difference in what tone she resists you. If she is enjoying the sex there is only really one reason for her to resist you (if sex is otherwise safe). She wants to feel your masculine essence. Women love to be dominated. She tests your core by pushing you a little, hoping you will push through her resistance. This is not done by using violence or extensive physical dominance! There might be many ways to address this but I love being playfully dominant. Something along the lines of:
You: Turn around on your knees and bend over.
Her: No
You: (playfully with a little smirk) Is my little girl being naughty? Naughty girls need to be punished.
Her: I'm like a little angel
You: I bet you are. I think you have been very - very naughty. Now lay on my lap for your punishment. (strong eyecontact, patting my lap)
Her: Nooo I'm nice
You: (Just stare and pat. She will bend and things flow on)
It all needs to be congruent. If it doesn't feel good to you start out small. After starting to dominate one or two girls, you really reallise how much girls love it. After this its very natural and easy to act dominant in future interactions.
Also if she really resists some advance of yours that seriously undermines your dominance, do NOT reward it. You can persist only till certain point after which things will start to backtrack. If it won't work, remove all attention. Women love attention. If you take the attention away, by say, starting to sleep or just leaving to do something else (without saying a thing), she will start chasing and get horny after a while. Hope this helps. Peace.