It all depends on the woman. The easiest positions are probably missionary or her on top.
Doggy doesn't work if the girl is thick.
I'm into SPH and hooked up with a very firm thick black girl that was happy to indulge my fetish.
She put that round ass in the air and dared me to try it. There's nothing more humbling than not even being able to penetrate a woman. She laughed at me and I never felt more impotent in my life, but I loved it and we had fun.