All you need is:
Water Bottle (With water in it)
Water Bottle Cap
Nut and Bolt
And a camera
Step 1: Make the Cap
Note: Make sure your bolt is the correct size to fit in your tripod slot on your camera
Once you have your hole, push the bolt through in, and screw on your nut, like the picture below.
Step 2: Use It!
IMPORTANT: Make sure you have water in your bottle, the water weighs the bottle down, and prevents it from falling.
If you are worried about water spilling on your camera, you can put a ring of glue around the bolt to seal any cracks.
I apologize for the short instructable, this project is so simple, theres just not much to say about it.