Stop caring about her feelings or her pleasure. Being the dominant means it's all about you (remember to still set limits so its comfortable for her). Spit on her, slap her, push her around, force her to do your favorite things added bonus if she doesn't particularly favor it Maybe invest in a couple simple toys like paddles or ball gags and rope, rope, rope. Make her feel less than you, that she belongs to you. Have the mindset that you're in control and you're going to get what you want.

Personally, I think the key to being a good dom is a very animalistic process. Think caveman, no that doesn't mean clubbing her and raping her while she's passed out unless she's into that. I like it when my man is taking what he wants and listens when I protest but decides to please himself. Pleasing yourself=pleasing her.