I have a tendency to slide the hips more that rotate them.

Any good drills for getting more rotation?

One I have found is to put a clubshaft resting lightly against your left hip and then on the downswing, rotate inside the golf shaft. If you slide, you will dislodge or move the shaft.

The shaft should not be anchored too much to prevent injury, but having it there seems to make it easier to rotate and clear.

Try turning your left toe in

try checking your weight distribution and your posture. Get the weight on to the balls of your feet and your knees over the balls of your feet. This will help your hips work correctly.

Try widening your stance. I had the same issue until I was told to widen my stance alot more than I had thought. I am 6'3" tall and was sliding more than I wanted. Once I made this change it allowed me to slide less but yet open my hips faster. Give that a shot.