An unaltered wine bottle can't function as much more than a bud vase. The neck is simply not wide enough to accommodate more than one or two flower stems.
If what you want is a bud vase, then great -- you don't have much work to do. As with all wine bottle crafts, start by cleaning the bottle thoroughly. Remove the labels and paint (unless you like them, in which case your project is going to be really easy).
You might decide to leave the glass unadorned. For a vase, decoupage -- the art of decorating a surface with paper cutouts -- can be a beautiful option. Decoupage images are traditionally affixed to the inside of glass vessels. Since your vase will hold water, you might want to ignore tradition on this one. Glue the images to the outside, and then coat with several layers of acrylic sealant or varnish to achieve an even, translucent surface [source: National Guild of Decoupeurs].
If you'd like your vase to be a bit more capacious, or you simply want to remove the threads of a screw-top bottle, it's time to enter the world of cutting glass. You'll be removing the neck of the bottle and smoothing out the edges of its new mouth. This sounds a bit intimidating, but it's mostly a question of having the right tools. You'll need a tile cutter, an axis glass cutter, a stained glass saw or a diamond-bladed rotor saw.
The cutting method will vary depending on the tool you're using. Usually you score the glass and then make a controlled break. Take it slow, wear your safety goggles and follow the instruction manual. If you've never cut glass before, try it on a few practice bottles first. (This may mean you need to drink a few more bottles of wine. No one ever said art was easy.) Smooth out the new edges with a carborundum stone, an emery cloth or a buffer wheel.
On the next page, we'll look at ways to create something more complicated: a chandelier.