Some excercises I did :
(Do it on all strings)
7h8p7h8p7 etc with your pinky and ring finger
7h9p7h9p7 etc with your pinky and middle finger
Just think of any variation you can imagine,
Start slow and stop when it hurts!
This is also a great excercise for independent fingers
5h7p6h8 and 8p6h7p5
Hopes this help some

Mark.