To stop the sticking I just lay carpet over where im packing in/shaping. It wont stick to the carpet. And once youre done just take off the carpet and the dirt is buttery smooth
You can also use spray oil. Better yet, just bring along a bucket of water and dip your shovel every now and then.
ya true I have a spray container thing I use for watering my jumps and berms that ill just spray my shovel with... But I've found clay sticks to a wet shovel much more than dry one