Heres a few of my lamps -
These fairy lights are mains powered but you can get some really lovely battery powered fairy lights, (easily found online any time of year). I usually use a string of 20 lights if I'm using mains powered lights but if you're using LED battery powered lights then a string of 40 should produce the same amount of light.
The only other things you need is a drill and a 9mm drill bit that can drill safely through glass, (so either glass and tile drill bit or a diamond drill bit,) and an open rubber grommet to plug the hole.
So I begin by drilling a hole near the bottom of the bottle. When drilling it's best to go slow and let the drill do the work - you don't want the bottle breaking on you! And please please wear goggles, gloves and long sleeves just incase! Make sure you wet the hole continually while drilling to get rid of glass shards and keep the bottle cool.
Once I have drilled the hole I will leave the bottle to completely dry for a few hours (over night if you can) before inserting the string of lights into the hole you have drilled holding the bottle upside-down.
To finnish the lamp I cut a rubber grommet to size to plug the hole, this makes it look a bit neater and keeps the lights in place.
If my instructions are confusing (which is very likely) I will answer any any questions you have.
Enjoy!