Sometimes you can't help but set up camp in an area where the soil is very stony or firm, especially when bush camping. This can make it incredibly difficult to drive a tent peg into the ground or maybe you simply forgot to pack tent pegs.
You can simply tie the guy ropes around large rocks or if you have lots of little rocks and some plastic bags you can fill the bags with rocks and tie the guy rope to the plastic bag. Will work just as well. Just remember to take you bags with you when you leave but leave the rocks.