The size and the shape of the camera mount will be determined by two things, the planned use and the size of the camera. A camera that is used as a security tool (e.g., in a bank or business) is going to be held differently than a camera used for filming or photography. Knowing what you will be using the camera will go a long way toward designing something you can use easily. Also, if you have a large camera (better for filming than anything else), your mount will need to be big enough to support that weight and make it easy for you to hold.
Most cameras have the ability to be mounted to something via a screw mechanism, usually found on the bottom. This allows the camera to be mounted to a tripod for smooth filming. However, if you have a bolt that fits this screw area, you can fashion your own mount. If you have a small camera, drill a hole through a pipe and fit the appropriate size bolt through the hole. Screw the camera onto the bolt and mount the pipe on a wall using a mounting piece (this is a piece that screws into the end of a pipe and can be screwed into a wall or ceiling).
Cameras for photography or filming will require a different set of materials for their mounts that will help you control the camera better. To make a steady-cam mount, for example, you will need weights to counterbalance the camera, several pipes that need to be fitted together in a T-shape and the bolts that will attach the camera to the mount. Look for things that have other uses that might also hold a camera. For instance, fix up a mounted bicycle headlight to be used as a camera for a bicycle or attached to a pipe as part of another mount.