I have the CH Figherstick, which is a good stick but has the usual problem found in most gaming sticks: it's too loose. So I cut a couple of rubber rings, about 25mm thick, off an old bicycle tire tube, rolled the two rings up making two fairly strong 'rubber bands', which I used to reinforce the weak springs hosted in the stick's base.
It works pretty nice but the tube rubberbands dont last forever, they break after a couple of months of heavy usage. No big deal though, it takes 10 minutes to make 2 new springs off the same tube and replace the old ones.(one tube lasts years)
I made a couple of pics to help understand the concept, not really so great artistic value but it may be of help if I didnt explain well enough.
Pics Here