Here's about the simplest strap you could make... but as with most of my DIYs on here, it was created out of a certain necessity. I recently purchased a solid pocket shooter - testing my theory that I might just take more photos if I had a smaller camera. The size is certainly more convenient, but I still am not used to having such a lack of grip. I didn't want to use a long strap all the time, so I came up with this.
It provides just the right amount of handle, but still be very pocketable. You'll need a small strip of pliable, yet strong leather. I'm using a small piece of the leather we use on our bags, from SB Foot tannery in Red Wing, Minnesota. About 4.5oz weight works really well for this.
Cut your piece into a 3/8" strip, about 22 inches long. If you need a longer or shorter grip, adjust to your preference. One one end, we'll use an oblong punch to create a slot - about 5/8" from that end. I also cut that end at an angle for decoration.
On the opposite strap end, I thinned the overall width with a rolling blade and ruler. We'll be tying an overhand knot here, and it looks more elegant with less weight. I thinned about 5.5" length of this end, to have some overhang after tying the knot.
If your camera has loops like shown, you're set. If you have a lugged camera, you can buy some small rings to attach first. Make sure your knots are big enough to keep from slipping through the rings. Or, if you're using detachable rings, you can use the slotted end on both sides.
Feed your piece though the slotted end first, and smooth out the curve. Insert other end though the second ring and knot to the appropriate length. Then cut the overhang length to whatever looks/works best for you.