Parts that you will need:
1) ~2 feet of 2x4.
2) Small sheet of plywood. The exact size isn't real important but it needs to be about 6" longer than the longest bottle you want to cut and 6" wide. My sheet is 2'x6".
3) Plumber's epoxy putty (~$2 at your local hardware store). You'll need ~ 1 oz.
4) Cheap glass cutter ($6 on Amazon).
5) 0.25" bolt, 6 inches long.
6) Wing nuts and two large washers for 6-inch bolt.
7) Rubber leg tips ($1.50 at Home Depot).
8) Five 3" wood screws and one 1" wood screw.
9) Small washer that can fit inside the rubber leg tip. I used a plastic one.
10) Small cloth rag.
Tools: The normal stuff like drill + bits, screwdriver(s), and saw. As noted above you'll need a bit that can drill metal.
Step 1: Bottle stabilizer
1) Cut a hole into the bottom of the rubber tip. You want the hole just big enough to fit the 6" bolt.
2) Insert the bolt. We want the tip to be able to rotate freely so we need to in insert something to keep the epoxy from binding with the bolt. Stuff a washer into the rubber tip so that it lays flat against the head of the bolt.
3) Cut off a good chunk of the epoxy and knead it so the two parts mix up well.
4) Stuff the epoxy into the rubber tip as tight as you can and form it into a rounded cone.
Set it aside to allow the putty to harden.