I bought a good quality gizmo that looks like a sweater or shoe organizer for a closet. It doesn't work well because things placed on the shelves slide forward. So don't bother with one of those.
Last year someone posted great detailed instructions for building shelves. Sorry, can't remember who and I didn't follow up and build them because I'm paranoid about drilling into the side walls and I'm not handy. But the instructions were awesome.
Now that I've been using my Bambi for two years, I find I hang more stuff than I though I originally would. I just slide three 11x6x8 plastic bins from the Container Store into the lower shallow section of the closet (basically for packaged food) and one large flat bin on the bottom for extra paper towels, TP, etc.
I'm sort of glad I never made the extra shelves so I can put jackets in the closet and have them out of the way. Then again, I'm a woman and have the right to change my mind, so I might think differently next season.