A tripod is the best way to keep your camera steady, but there are ways to increase photo quality without using one. The most stable way to hold a camera is with two hands. Your right hand should hold the right end of the camera, with your index finger ready to push the shutter release (this hold comes naturally to almost everyone). Your left hand should support most of the camera's weight -- that usually means the other end or cupping the lens, if you have a camera with a large lens. Keep the camera as close as you can to your body for stability, and you can lean against something solid (like a door frame or a wall) if you need extra stability.