Let's see, I already mentioned dimels and Rev band deads...
Keep doing the GMs.
Bent over drags.
Heavy swing throughs.
I like kneeling squats too, but some people really feel those in the hip felxors (in a bad way).
...it's a pretty simple move, so just about anything the forces the hips through will hit it. Just try to use the same stance you deadlift in, and maintain the proper back position while doing it too. A few weeks of those worked in, and you may see a difference.