Make a cheap, incognito, camera bag. If you don't like carrying an expensive camera bag that has "steal me" written all over it, but still want to protect your gear inside an ordinary bag, this is the perfect solution. As this is being written IKEA has some approx. 2€ cooler bags called Kylväska Tårta in their food department. I bought two of these to make a camera bag with internal dividers.
Split the seams to remove the side walls below the zippers on one bag. Then use the side walls to make dividing rooms for lenses and other stuff in the second bag. All you need is a sharp knife and a sewing machine.
Once you have freed the side wall, measure the length you need for the dividers, and mark them with a pen. A double seam with the sewing machine fixes them in place. The foam padding is thin enough that it is easy to sew through with a household sewing machine.

As an added bonus you get a 50cm black zipper to use on other projects!

Step 1: Ambitious Ideas.

Use the extra top and bottom panel to double up you bag for added protection. I sewed the extra top/bottom panel inside the existing panel for added protection, to do this you have to remove about 2 cm /1inch of the length of the panel you are inserting, as it will have a slightly shorter circumference. I sewed it to the top and bottom sides only, for ease.

Other things you might do:

Add a cardboard floor in the bag for structure and stiffness.

Or sew Velcro to the internal dividers to make the bag configurable for several cameras. But the bags are so cheap I would rather just make more of them!