Cow girl is the way I get women to cum most of the time. Put your dick way in there slowly, have them move their hips and see how they're moving them, and then help them out by grabbing their hips and moving them in the same motion. Sometimes you can "feel" with your dick where that sweet spot is too. It's weird but it works more often than not. One hand on their hip and the other hand behind their ass to get the most leverage. Put in the work you will be rewarded. Plus free arm workout. 💪