When I go to the track, I carry everything in a big roll-around Eagle Creek duffel bag -- this way I have everything I need in one package, I just dump it in the car and then just roll it to the infield. I never have to collect stuff, and it has a track helmet, track tools, any skinsuits, keirin gloves, my track shoes, etc. Over time I ended up with everything just for track (different track pedals anyway, the clothing is different, etc., so it isn't that much of a hassle or cost).
I got a couple of the Eagle Creek plastic-lined mesh bags at REI for about $6 apiece. One is big enough to hold the chainrings, which each have their own Ziploc freezer bag so chain lube doesn't get all over, plus the bag has a couple dish towels that I use to clean the rings off when I have time. There's a small mesh bag I stick inside with all the cogs. I keep my prime set of cogs in that kit, plus I have a pocket on the top of the duffel where I keep a bag of safety pins, a few pens, 3M spray, folding allen keys, a multi-tip screwdriver, a handful of zipties, and the other stuff I tend to need at a race and that other riders tend to want to borrow. There I have a few extra cogs left over from some old wheels that are available for loan. Most riders know that they can raid that top pocket if they need something quickly during a race.
This setup works well, keeps everything clean, and I can roll the duffel in one hand, even with a pair of wheels or rollers strapped on, and hold the bike on my shoulder with another pair of wheels or a folding chair in the other hand. Not enough hands to carry the cooler full of beer, but the system is almost perfect.