I found this technique in a magazine a while back, and initially used it to create a lace curtain for a bathroom window. Over Christmas it came in handy for this idea I had for a button-up cowl. I made one for a friend and one for my sister-in-law.
The technique is actually fairly simple, really only using double crochet stitch ("single crochet" if you are using American terminology). The pattern is created by every third row being made up of loops over something with a broad diameter - the "broomstick" of the title.
When working this in crochet cotton for the lace curtain, I used a 10mm knitting needle as my "broomstick". For this chunky yarn, the handle of one of hubby's golf clubs turned out to be the ideal diameter, so strictly speaking this is golf-club crochet! The buttons were sewn onto the foundation rows, and align naturally with the loops forming buttonholes. There is also the added advantage that they can be buttoned into any of the loops, making the cowl tighter or changing its shape as required.
There were then three rows of double crochet to form the foundation rows/button band.
On the fourth row, and without turning the work, the stitch is taken off the hook and looped over a broomstick. Using the hook, the yarn is drawn through each stitch except the first, and another loop added to the broomstick. This leaves a row of stitches more similar to knitting than crochet.
Again, without turning the work, the loops are then taken from the broomstick in groups of five. So the first five stitches are lifted off the broomstick onto the crochet hook. Yarn round hook and pull through all the loops followed by a chain stitch, which secures the five loops together. Then five double crochet stitches are worked into the loops. This pattern is repeated until all the loops have been removed from the broomstick.
The work is then turned with a single chain, and a double crochet stitch is worked into each stitch to the end of the row.
These last three rows (4-6) form the pattern, and are repeated until the piece has the desired length. Because of the large loops it grows fast, and so is extremely satisfying!