Since I keep the shades on my lenses at all times, it was a real pain to try to reach down in the shade to take off/put on, the lens caps. So I ordered a Lens Hoodie to see if I'd like it. I love it!! It fits snugly over the shade, and keeps the dust, etc., off the lens. It has an additional harder circular piece in the front of it, to further protect the lens.
Hoodie Lens Caps - LensCoat
OpTechUSA also makes one, that I ordered yesterday for my other lens, to compare with the lens coat. This one is less expensive, and does not have the harder circular piece in the front of it. I'll report on that one when it arrives, and how I feel with the comparison of the two brands.
For those that leave their shades on their lenses, I would highly recommend trying one of these products, I think you will be very pleased with the ease of using them, rather than the lens caps.