I've been a long-time instructable consumer, but this is my first time creating one so go easy on me please! Oh also, if hanging fixtures aren't your thing there are a bunch of other cool jar light 'ibles like this one .
Step 1: Tools & Materials
big jar - i used a bell mason jar from the hardware store $13 for 12 jars so... ~$1 per jar
pre-assembled light socket and cord - i used the "hemma" from ikea - $6.99
light bulb that fits through in the jar
some sort of cutting implement. I ended up using an exacto knife, but i'm sure there are better ways
Step 2: Cut the Hole
now for the cutting part. at first i tried to use a hole cutter on my drill, but this didn't really work out so well. I ended up just using a box cutter to cut through the lid. keep in mind that the hole doesn't have to be perfect because it won't show and you can adjust everything when you are screwing in the socket. all you need to do is make sure that the end of the light socket can fit through the hole.
Step 3: Attach the Socket
first, unscrew the attacher thingy from the the socket and unscrew the lid from the jar. then, stick the socket through the hole in the lid and screw on the attacher thingy on the other side of the lid so that it holds the socket in place. As you tighten it on you can adjust the placement.
if you took the ring part of the jar lid off, put it back on over the cord.
Step 4: Now Put It Together
i like the look of the long low-watt lightbulb best. The red lightbulb looks cool as well. The regular lightbulb just looks kind of so so. i think it would also be cool to find either some super low watt long bulbs or do like this instructable and put it on a dimmer.
my next step is to add a switch. wish me luck!
i included a picture of the restaurant (Straw) in sf where i originally saw these lights.