In a well ventilated space, dab solder joints with e6000 or other adhesive of your choice.
Position the strand on the pleather harness. Dab e6000 adhesive onto the larger NeoPixel pieces and the LEDs that will sit on ends and corners and attach to the harness and clip into place. Use e6000 and thread to tack down the rest of the pixels.
Print a 3D Printed Battery Pocket for your Lithium Ion Polymer battery or sew a battery pocket out of fabric and attach to the side of the harness.
Plug the battery into the extension cable and the CPX and turn it on.
Use the slide-switch to turn on and off the LEDs. The switch itself doesn't turn the board off, but allows you to go a little incognito with the lights.
Use the left button on the CPX to cycle through some FastLED examples. Customize your sketch by creating new modes and palettes!
Use the right button on the CPX to activate the pretty VU meter example sketch.