I have a pair of gloves with little dibs that help move the fabric - like gardening gloves, they have little dots of some sort of plastic. Try to just guide the quilt sandwich, let the walking foot do the work - don't push or pull the fabric.
I also find I have to keep reminding myself to relax my shoulders - I seem to manage to get them all bunched up - not sure if my chair should be at a different height or I'm just not relaxed enough!
Enjoy!