I was inspired to make these via: http://hrrrthrrr.com/ she had a great tutorial about the how to.
+And you could either sew these by hand or through your sewing machine, which is what I did.
Start off by making a template for yourself of the light and also of the connector piece to copy onto the felt squares with your marker. Cut out all pieces and line up two pieces of the light felt and one strip of the connector piece folded over and simply get to sewing. If you wish you could stuff these to make them appear even fuller but I found that it wasn't necessary and took a lot more extra time.
I also sewed the outer edge of the connector piece to show stitching, again not necessary but I think it makes them stand out a bit more. Lastly string your ribbon through a needle (a large needle) and thread it through the connector piece of the lights so that they don't all bunch towards the center.
Like hrrrthrrr says its a bit time consuming but worth it in the end and would make a great family project with the kiddos.