To solve some of your festive season problems I present you a simple guide on how to make your own bottles with a light string inside. These are simple and pretty cheap to make while still making a stunning decoration and have proven themselves as a great gift too!

Step 1: Stuff You Will Need

1. Drill
2. Diamond crown drill bit (12mm or 1/2" in this case)
3. 20 white LED light string
4. Bottle
5. Bowl
6. Rag (optional)
7. Water

Total price in my case - approx 10$ (raised this drill from the dead).

All of the stuff listed is for what I've tried. You may want to experiment with using:
A spade drill bit instead of diamond crown (I don't like spade bits).
A LED string with more or less lights (20 look just right though)
Something else instead of bottle (I'd love to see examples)
Running water instead of bowl filled with it (risky, rag is a must for this one)

As for the color of bottle, Ill post some examples later in this instructable, but I like those dark brown ones the best, since the glow is very nice and warm, when on, and you can't see much through, when off.

Side note: Since it is possible that LEDs are of different size it's possible, that you will need a drill bit that is smaller or bigger (most likely). When measuring, take into account, that it is the LED and two cables that should fit through the hole! For my 12mm drill a 9mm (0.35") (at widest point) LED with 2.5mm (0.1") cables fit just right.

Step 2: Let's Dooooo It!

First of all remember, that water and electricity doesn't mix, so be cautious, if you have one, use a pneumatic tool.

1. Keep your drill at a safe distance and fill the bowl with water.
2. Put your bottle in the bowl, water should be a bit above bottle (0.1" is more than enough), it will be easier if the bottle is filled with water, so it doesn't float. If you can't find a suitable bowl and are using the running water method, make sure to put a rag under the bottle, so the hard surface (i.e. tiles) doesn't scratch it.
3. Dry your hands if they are wet.
4. Take the drill and hold the bottle with the other hand so it's all steady.
5. If your drill has an additional handle to the side, make sure it rests on your forehand, that way it's easier to keep it steady and start drilling at an angle somewhere approx 30 degrees should be fine. This will make the starting groove. It's important to keep drill steady at this point, so the bit doesn't scratch the bottle.
6. Eventually straighten the drill to be perpendicular to the bottle. Drill at low to mid RPM, don't rush it, patience is your friend here.
7. After drilling through pat yourself on the shoulder.
8. Wash the bottle and let it dry.
9. Clean the inside of it from water stains and let me know how you did it (seriously, write a comment about that).
10. Put your LED string inside through the hole.
11. Enjoy!

Step 3: Other Stuff

The first picture is from last year, when I did 3 different colors. From the left: light green-brown aka "dead leaf", amber (like cover ones), dark green. Pick yours. :)

The other picture is just what would you see inside, some off-topic.

Just so you know, I have not tried, but it is indeed possible to make these beauties without any drilling and long cables!
There are strings available on eBay which are battery powered. You can put them through the neck, plug the bottle to hide the cable a bit and voila! I have contemplated about modifying one of these strings so the battery pack would actually fit inside the bottle. Just food for thoughts, let me know if you make something like that!