Do you have the old poles, or the new tent-style pole? I have both and use the tent one exclusivevly now. Much smaller and easier to store. I don't like screwing clamps etc. onto the pole, so I prefer to secure things in a way so that they come off easily. The product I use the most is bungee balls - very broad application capability in a lot of things, not just disc golf, but I secure various things to my cart pole with them. Just wrap it around a few times around the pole, one at the top, one at the bottom, and you should be good to go.
http://www.homedepot.com/p/Riversto...M9I9io_CtR-aoY4bbp3NtxoCB1Hw_wcB&gclsrc=aw.ds
The quick fist rubber clamp is another easy on/off product with a lot of potential.
http://www.amazon.com/Original-Quick-Fist®-mounting-equipment/dp/B000CQPANY One at the top, one at the bottom, that should be even more secure, and maybe even faster and easier to access.