When I travel light, those thin grey Canon Soft Lens Pouches seem to do fine for just covering up my lenses. Of course any lens case is better than no case to minimize dust, moisture, and scratches. Now when traveling heavy with a wide assortment of lenses I have to carry a bigger bag. More lenses + Bigger bag means equipment is just stacked one on top of the other. I don't like over using dividers in the travel bag because it's just taking up way too much space. Instead I thought I'd just individually wrap up each lens with a beefy Neoprene case. Neoprene is the same material used on Scuba Diving suits so it's quite elastic, soft, but still durable. Much better protection than the standard grey bags that come with most Canon lenses. Obviously, these things are quite cheap coming from overseas starting at only $2.38 + Free shipping. I've placed an order on a variety of sizes, and soon as they come in i'll show which pouches fit which lens. Check out the huge variety of Neoprene Lens Protective Bags.
If you're looking for something even more 'beefier' than the Neoprene Lens bags, foam padded ones are a bit larger, taking up precious bag space, but offer better protection against bumps and impact. Many of these are also wearable around the belt look or shoulder sling strap. These suckers start UNDER $10.00 + Free Shipping. Check out the variety of Foam Padded Lens Protection bags.