I'll share mine too. It's an ultra cheap, ultra space saving method.
I have a stack of 1/3 sheet sandpaper. Instead of glass, I have a chunk of granite counter backstop a bit longer than a sheet. I clamp this into my little front vise, then clamp a sheet at a time onto the thing. For most grits I can get away with just clamping one side. For some I have to put tension on the paper and clamp both ends, which I accomplish with a couple chunks of angle iron and some quick-grip clamps.
I gravitated toward the clamp method because I didn't have enough chunks of granite just the right size, because I find it's a real bitch to change paper, and because I wear out paper so frequently.
I run through 60, 100, 150, 220, 320, 400, 600, 800, 1000, 1500, 2000 for the backs, and if I'm putting an edge on for the first time. For touchups I'll start at 600, and if that isn't doing any good, I'll go down as far as I have to in order to get aggressive enough to do the job.
I use more 60 grit than anything 20:1, and I'm coming to the conclusion that I *must* get a good wheel and a proper tool rest for my grinder. Changing the angle of something with sandpaper SUCKS!!!
I'd like to eventually have one chunk of granite per grit, and rig some way to hold them all down. Sharpening an entire set of chisels at the same time is tedious. Set the angle, swap paper 12 times, set the angle, swap paper 12 times....
Anyway, it works. My stuff is all very shiny, and verrry sharp. For awhile. I'm finding my scary sharp edges dull very quickly, and I'm beginning to experiment with less time-consuming, less-sharp methods. No point getting it ultra sharp if it's only good for three cuts before it has to be honed again. (Probably I need steeper, sturdier angles or something. I'm experimenting, which is why I'm eating up so much 60 grit, and so many hours spent sliding things back and forth.)