I just finished my first wearable project. I built it to add some visibility to my workout jacket for the winter months. Although I think I might have overdone it a bit with 10 neopixels. I'm tweaking the programming to limit the number of pixels on so it doesn't blind anyone coming up behind me.
Originally I was going to just sew the neopixels to the jacket but then I decided to use a separate piece of fabric so it could be removed for cleaning. Plus it would allow me to change jackets depending on how cold it might get.
I followed the guide from the neopixel suspenders for sewing the positive and ground leads. Then I hand stitched the data line between each pixel. I left a small pocket behind the Gemma and stitched the battery in to secure it.
I used some safety pins to hold it to the back of the jacket. Now I just need to adjust the programming so it's not too bright.