Check out a tutorial after the Jump :)
This may be a little bit unnecessarily detailed tutorial on how to tie some string, but it took me a little while to figure out the best, easiest way to tie them on there and keep them on there so I figured I would share :)
You will need:
-jars with some sort of a Lip at the top(old food jars would be great for this.)
-twine or wire
ONE: Start by cutting the twine into aproximatly 3' pieces. You will need 2 per jar.
TWO: Start by tying a knot an inch or two away from the middle
FIVE: Wrap the two strings on either side a full loop around the neck then back around and tie a secure knot.
SIX: Now take the other side and do a full wrap around the neck and knot that side so that you have a knot and two strings on either side. The more wraps and knots the better. It just secures it better so you don't have glass and fire falling from the sky :P
SEVEN: Use some glue to secure the knots and the twine to the glass.
EIGHT: Now Fill the jars with sand. They sell sand at the dollar store and they have lots of different colors I used a half of a container of sand per jar. Or there is always the good 'ol beach :)
NINE: Now put a few candles in them and hang them up!