I sketched out the circuit between the Gemma, LEDs, and microphone. I drew the circuit path for the LEDs and Gemma on the under panel using a fabic pencil and tacked down the LEDs with a small amount of normal thread. There was extra material at the ends that I folded it over to make a small pocket for the lipo battery.
After sewing on the LEDs, I tested the connections using a multimeter. I also added a small amount of clear nail polish to the end knots, as this particular conductive thread I'm using frays very easily.
The extra material at the end will also work as a sort of bridge for a few of my circuit paths that would otherwise cross. By using an embroidery stitch called couching, I can tack the trace of conductive thread to the top and bottom while letting the fabric work as an insulator.
Next step, attaching the LED panel to the dress so I can sew the circuit between the Gemma and mic.