Step 3: Plan the light layout
The center core of EL wire is made of solid copper, and like any solid wire it will break due to fatigue damage after repeated bending. On the human body, the elbows, knees, shoulders, and hips undergo the most movement. You can make the electronics last longer by mounting EL on areas that don't flex as much, and using stranded insulated connector wire (which can flex) to join the glowing pieces together inside the garment.
Plan the placement of EL wire with temporary markers like pieces of string, pins, or stickers, or make a sketch on a digital photo of the garment. You can follow the seams, or add axtra lines as desired. Decide which sections can be lit up with a single continuous piece of EL wire, and which will require multiple pieces.
Then, decide what path the wire will take for each section, and mark the entry and exit points. To make sharp "T" shaped junctions, you may need to run the wire inside the jacket at some locations.