I've already written a short bit on modifying gun cleaning kits to have a straight wood handle as opposed to the horrible plastic T handle. This next bit is about making a storage tube for the new, streamlined kit. This is simple.
Take a cardboard poster mailing tube (my wife orders the occasional poster for her classroom, so these are in no short supply at my house) and cut it to the length of the longest rod, leaving about 3/4 of an inch extra for the cap and space. The cap on one end is usually stapled securely in place, and the other end taped. Cut from the taped end.
After cutting to length, seal the freshly cut end by running a band of plastic packing tape around the tube, leaving 1/2 inch or so overlapping past the end of the tube.
Cut the overhanging tape into 1/2 strips, then fold them over, sticking them to the inside of the tube. This helps keep the business end of the tube from fraying so quickly.
That's all there is to it. A 1 1/2 inch tube will hold a pistol rod and 3-piece rifle rod, with room left over for brushes, jags, and patch loops. Best of all? It takes up very little room in my range box.