We had these lights above our breakfast bar in our old house. They are made out of a large mason jar with the bottom cut out – done very carefully using the Bottle Cutter Kit. This is actually the hardest part of the job.
We used 1.5 quart jars which are very large, and hard to find.
For the frosting we used spray glass froster which diffuses the light so that you get a soft warm glow instead of the harshness of a bare bulb. Just a light spraying on the inside is sufficient.
Here you can see the lights, one frosted beside one not frosted. It made quite a difference in how pleasant it was to look at.
You will find a tutorial on how to build a similar mason jar light fixture on in.gredien.ts.com
However! I think using this incandescent bulb in an unventilated mason jar is a mistake! Too much heat will build up which is sure to be a hazard.