Need Tips on how to better my “riding”

I’ve been with my boyfriend for three years & we’ve been having sex for almost 2 years I’ve always been nervous because I’m not exactly light but I’m not really “over weight” either but I do consider myself to be “bottom-heavy” so squatting can get easily tiresome. I want to get better at being on top so that he doesn’t have to generate all the energy but rather get some more time to lay back and enjoy like I do In the other positions. Any tips?