I use pearl cotton or the cheaper 'craft thread' you can find it next to the embroidery floss, and also can buy 24 or 36 skein bags of many colors for like $4-5 at Michaels, which is cheaper than the $1.35 a (bigger) skein costs otherwise. You can also use floss, but I don't as I like the look of the twisted ply pearl/craft thread.
You can decorate with trim or beads (I don't because I rather like them more grippable and beads hurt), but I wouldn't use beads on top, the pins might catch on them. What good is a pincushion if you can't put a pin in it?
Overall these take 30 min or less to make, time well spent and as much as I hate to say it, cute as a button!
MATERIALS and SUPPLIES: (for one shown in this instructable)Scissors, craft thread, craft felt, fiberfill and a soda bottlecap.
Step 1: Cutting the Pieces
Step 2: Ball
What to stuff with? I recommend simple fiberfill. Stuffed extremely densely. I normally will stuff some in, close it up and tie it off enough to get my stuffing stick in and continue to stuff it once knotted. I stuff so much in the"crunch" when you poke pins in and are extremely dense.
What about what you see many selling, the tradtional Emery sand that keeps needles sharp and clean? (that little strawberry on the tomato pincushions is an emery).
I hate to disappointing many that seem to attached to this mineral, but unless you are using vintage pins you do not need a emery at all. Using emery on any pin or needle say after 1970 or so is a waste, as well as it could damage the plating of said pins and needles.
Modern pins and needles are:
1: plated and do not tarnish!
2: hardened steel and do not dull!
Just stick with fiberfill, if you stuff it full enough it is more than abrasive enough to not only HOLD the pins in but clean any magical dirt that might stick to chrome.
Step 3: Outside
Start a knot on the inside bottom overlap and begin a simple whip stitch around the bottom connecting the bottom to the sides.
When you get back to where you started, go up the side seam.
Step 4: Stuff It!
Replace cap into sleeve, snug it on.
Step 5: Sew Sides to Top
Buttonhole or whipstitch are good, but anything works.
Step 6: Decorate!
When done decorating, go back in and bring thread out the bottom. No need to knot off. Clip!
You can decorate as little or as much as you want.
Step 7: DONE!
Then.... Stick a pin in it's it's done!