Here's a couple of things I highly recommend you should already have with your lenses. The day you purchase your new camera lens, the store will always suggest you buy it with at least a basic UV Filter. I'm not going to argue about the price and quality of the stuff they are pushing, but it's a very important thing to have. A basic UV filter isn't anything special that will dramatically change your images, but it will protect your front element from dirt, oil, dust, and most importantly scratches.
If you get a single scratch or mark on your lens, you're throwing good money out the door. Let the filter take the hit, and just replace the filter. If you walked away from the store without one, you need to at least throw something on there, and you'll find many for under a few dollars.
Next item to care for your lenses is a pouch or a sleeve. Even some high end Canon L lenses don't come with decent lens pouches, just a gray bag and a pull strap. Regardless, you need something, anything. Not only will it protect from scratches, moisture (throw in a silica gel bag into the pouch), but also dust. Dust finds it way into 'everything'. Neoprene pouches (same as surfing wet suit material) can be had for as little as $3 dollars.
Photo Video Camera Lens Pouches
Another inexpensive item you can grab for a single dollar or two - The Lens Pen Brush. Most of us don't have room for Compressed Air Cans. Those Liquid Bottles and Cleaning cloths are mainly used to clean up oil, but aren't the best for dusting off your lens. In fact, you should 'Dust before you Wipe'. Dust can sometimes be very abrasive and taking a cloth to it could be damaging.
If you see a few specs of dust on your filter, or in between the filter and your front lens element, don't reach for it with your finger. Don't try to swipe it with your T-Shirts (laundry softners have wax). Simply pull out your lens pen, push out the brush bristles, give it a good shake and then lightly dust away those tiny particles. You can brag about your thousand dollar cameras, lenses, and big budget shoots, but a spec of dust on your lens has the potential of ruining everything.
These lens pen brushes are so cheap, I purchased a dozen. I keep them everywhere. I'll use them to dust my laptop screens, keyboards, camera lenses, filters, and more. Small yet incredibly useful. There's a long list of things you should have as well, but these three very inexpensive items should give you a good start on maintaining your investment in lenses.
