US 4 DPNs (only 2)
scrap yarn, worsted weight ish. I don't know exactly how much, this star was made with a ball smaller than fist size. (Damn I need a scale!)
Needle and yarn size are absolutely customizable for whatever size star you'd like. Try to keep the gague relatively dense if you want to stuff the star afterwards.
For the large star pictured:
CO 30 sts. *Knit 2 rows plain (one RS one WS), then knit 29, wrap and turn. P 28, w&t. Continue wrapping and turning until 4 stitches remain unwrapped. Knit 4, pick up and knit wrapped stitch, w&t. P 5, pick up and knit wrapped stitch, w&t. Continue until all wraps are picked up.*
That is the basic structure, it is exactly the same as a short row sock heel/toe, for those of you who have done one, except "skinnier". It's really easily adjustable. For a five pointed star, repeat four more times. It can be done four times for a square, or more for a crazier star shape.
Smaller or larger stars can be made by using the same method, just casting on more or fewer stitches.
Once the knitting if finished, use mattress stitch to sew together the cast on and cast off edges. Sew one of the remaining 'holes' in the star shut. Stuff with polyfil, stitch the other hole closed. I feel like this pattern is so simple and intuitive (once you have short rows down) that I shouldn't even take credit for it. Making short rows work for me and seeing how I can use them in construction is one of my knitting goals for this year, and I'm looking forward to seeing how else I can use them.