I use a big spike with wire wound around the top and made into two loops. I have a stooge line like Glen describes, but mine is muddy brown from years of use. There is wire pin about 6 inches long which goes through the two stooge loops and the loop on your airplane. I leave some loose line next to the airplane so that I have to take up some slack before the pin comes out. I throw the stooge line handle away from me so that it does not get entangled in my feet (been there, done that[:-]) If the airplane does not release as planed, just stand there holding the handle and thinking pleasant thoughts until the engine stops. No system is foolproof, so think about what you are doing and why, and do it the same, without fail, every time.

One downside to flying by yourself is that you cannot concentrate on flying as much as you might like as you have to maintain situational awareness of what is going on around you. Also if anything goes wrong, you deal with it on your own.