Are you driving them back, or are you doing it when they are moving towards you? I guess it doesn't really matter much...but if you're just hooking the leg and pushing them back then you are doing it wrong.
After hooking that leg you should be able to do pretty much what you want with his upper body. Since you're taking the weight from one side of him he should have the motion to turn and fall to that side. Your hands should be able to assist in turning him a bit, but ultimately you should be able to easily land in yoko shiho/side control
Can you post a vid? Makes it infinitely easier to offer specific advice.