Because we are building on the HalloWing and using hardware that is directly supported by it, the electronic aspect of the projects mostly consists of plugging things into the HalloWing: speaker, PIR, NeoPixels, and a battery. Two additional things are the touch pads and a USB extension.
Since the HalloWing has 3-pin JST connectors for the NeoPixels and PIR, we can clip and tin the ends of two 3-pin JST plug/cable assemblies. One can be connected directly to the PIR sensor (after carefully removing the connection pins and cleaning the holes with desoldering braid.
If you're less than comfortable with this, be sure to get JST cables with female ends that you can just plug onto the PIR's pins.
The other JST plug/cable will be used for the NeoPixel ring, but not until the physical assembly.
Now make the USB extension. You will want to have the USB connection available for recharging and reprogramming. Separate out about 14cm (5in) of the silicon ribbon cable. separate it into 2 5 wire pieces. We'll only need one. Strip and tin about 1mm (1/16in) of both ends of each strand. Solder one end to the USB micro-B breakout connections, and the other to the USB micro-B plug. A quick way to ensure you have the connections right is to plug the plug into the breakout and use a continuity checker to find the common pairs. Connect those pairs. When soldering to the breakout, don't put the wire ends through the holes. Instead, solder them flat onto the pads. See the photo below.
You can also use a pre-made extension cable if you don't want to DIY
The final real bit of soldering is to make the touch pads. The design was made to use double-sided 20mm x 80mm prototyping board with plated through holes. Solder a strand of thin wire (wirewrap wire works well) so as to connect all the holes on one side of the board. Clean up the other side with desoldering braid to remove any excess solder. Then clean off any resin. Isopropyl alcohol works well.
Now on to the physical construction.