So, you searched the World Wide Web for a cheap camera strap, only to learn that some aren't cheap at all. But you can make one yourself. You need only a few things. A polypropilene webbing, a half-circle steel ring, a carabine hook, a particular type of screw, some strong nylon thread (something similar to this: Nylon thread) and a needle. If you have a sewing machine, then making the ring shape of the strap is a bit easier.

Supplies

About 1,5 m (about 5 feet) of polypropilene webbing, 25 mm wide (about 1 inch)

One or two carabine hooks 40 mm x 4 mm (I used two)

One or two half-circle steel rings (I used two)

One camera screw (replacement part for camera straps)

About 2 m of strong nylon thread and a needle (or sewing machine)

Step 1: Assembly

I used about 1,5 m polypropilene webbing, because I wished the steel ring-carabine hook-screw to be at about hip level. If you wish, you can adjust the length on webbing so that everything gets lower. I opted for this length to be able to reach for the camera easily.

After cutting the webbing to length I used heat to seal properly the ends of the webbing, preventing it from unraveling. I inserted the half-circle steel rings on the webbing. I folded each end about the width of the webbing (25 mm on each end) and opted for a flat lock seam. Since I have no sewing machine available, I opted for manually sewing not only the edges of the square, but making an X shaped strengthening also.

At the end I attached the carabine hooks and the screw.

Step 2: The Finished Project

The image on the left is the seam, the one on the right is my finished project.

In this project you can use 40 mm wide webbing and 40 mm half-circle or full-circle steel rings. I considered the 25 mm wide webbing being strong enough, having an advertised strength of 255 kg.

I did not embelish my strap due to lack of a sewing machine. Making a shoulder pad without a sewing machine is more difficult (I don't say impossible though). It is not too difficult to add a shoulder pad or a lens cap holder (pouch) later on.

In the end (without the time spent gathering the necessary materials - travelling to the shop, waiting for the screws arrive by parcel delivery service), the whole project took me about half an hour to make.