A couple of ideas - if you are inclined to purchasing in bulk, ( TP, extra batteries, lightbulbs, detergent, etc.) this is a good spot to store the boxed extras until you are ready for them. You might also consider a false wall for hidden storage. Lastly, cutting a wood block ( or two) to fit across the back will elevate things, making them easier to reach.

I go to the dollar store and get baskets. of varying types and sizes to fit the project. My husband is terrible about neatness. So I just made things you could throw it in, he is pretty good most of the time. I even went to the thrift store got one of those flat back baskets with a handle, he screwed into the bathroom wall and our washcloths look like a bouquet when you stuff them in. and how about those bars from ikea, with the cheap hooks and other things you can hang, you can hang hair dryers etc. if you want. Although I have a stronger basket that is hair stuff. one is full of bandaids and skin medicine. You get the idea. You would be surprised how quickly you remember which basket is which and how easy it is to pull them out.

If you, or anyone you know, is capable of building a simple drawer to fit your closet shelves, you could attach undermount drawer slides to them to be able to pull them out. They only come as deep as 25" but if you mount them toward the back of the drawer bottom, they would pull out far enough for you to easily see the contents.

I agree that drawers are a great idea. They don't have to be custom built. You can purchase a closet system that has pull out shelves and turn the entire closet into one giant "chest of drawers" style storage. Place the once-in-awhile items in the top drawer, and label the front of it. It could turn into a real asset in your home.