This is a fun and festive project. EL wire adds a festive touch to my christmas tree. Note the blue-ish wire is actually very green. (My camera must not be in the holiday spirit.)

Electronics

6 meters of red el wire (2 packages of 3m)
6 meters of green el wire (2 packages of 3m)
EL Inverter and Power supply Optionally, you could use an EL sequencer, such as the one in my other 'ible.
~100ft dark green wire
6 jst extension cables
green heat-shrink tubing or electrical tape

Tools

soldering equipment, including iron, solder, wire cutters

If you plan to cut the el wire to size, you will also need:

jst cable (enough for each cut segment)
a magnifying glass (the corona wires are tiny!)

Step 1: Making Extension Cables

The EL wire comes with a short power cable so we need to make an extension cable. This is where the small jst excentions cables and dark green wire come in. The short extension cables have both male and female connectors on them, and the dark green wire can disappear into a christmas tree. We will be using a technique described in this instructable for twisting cables.

Measure out two wires, about 25 feet each and tie them to something.
Put the other end of the wire into a drill, and spin it to twist the cables together. Keep in mind that the twisted cable will be shorter.
Cut the resulting cable into lengths appropriate for your tree.
Cut the jst extensions in two and solder them to either end. Leave as little of the red/black wire visible on the female end as that will be in the tree. Polarity does not matter.

Step 2: Electronics

At this point, the wires are ready to go on the tree. You can either spiral them up the tree, or you can do what I did which was to cut hoops. Cutting into the wire is not for those low on patience; it can take some time and several tries to solder the tiny delicate corona wires. Here is a short tutorial on how.

As previously mentioned, there are two ways to go about powering the wires: going directly to an inverter, or using something more elaborate, such as an el sequencer.

To share a single inverter, it probably makes sense to make a splitter using the remaining short jst extension cables, one male to several female plugs. I do not have pictures of this because I went the sequencer route which has eight ports for el wire. This allows one to program patterns. The simple startup pattern that I use on my tree is available on github.