I go through phases with my hair. Currently, I wear it just below my shoulders, and I find that a hairband is a wonderful accessory for keeping hair out of my face. I had no idea that my current hair style would lead to a crochet epiphany, but it has.
Here is a photo of my favorite hairband:

and here is a photo of my favorite hairband with my must-have-but-as-yet-unfinished poncho:

Despite the fact that both the hairband and the poncho-to-be embrace the granny aesthetic, the two pieces don’t really work together.
So despite having plenty of other things I should have been working on, I ended up spending at least some of my crochet day working on a new hairband,
I had been thinking about the hairband-to-be for several days. I knew how I wanted the finished object to look, but I had no idea how to bring my vision to fruition. I wanted to base it on a granny strip, but I didn’t think that the foundation method I used for the poncho would work for a hairband.
This discrepancy between how I wanted it to look and the methods I had thought of for constructing the hairband had been festering for several days. Then, after some late night ruminating, I had a crochet epiphany.
Any time I would bring a crochet problem to mentor, a woman named Edith Proctor, she would tell me this:
It all starts with a chain
and as it happens, a chain was where I found the solution to my granny strip hairband problem.
Using my 4.5 mm hook and scraps of worsted weight yarn, I made a chain that was 72 stitches long, but any multiple of four will do:

Then, being careful not to twist the chain, I formed a ring by joining the last chain made to the first with a slip stitch:

After I completed the joining, I then chained three which served as the first dc of a 3 dc cluster:

From there I finished the cluster by working 2 dc into the ring:

Having completed my first 3dc cluster, I made a chain and worked another 3dc cluster into the ring until I had 18 3dc clusters with a chain-1 space between each cluster. (The number of 3dc clusters and chain one spaces is determined by dividing the number of stitches in the foundation chain by 4).
After completing the 18th 3dc cluster, I made my last chain 1 of the round and used a slip stitch to join the stitch on my hook to the 3rd chain of the chain-3 that served as the first dc:

Then I slipped stitched over to the next chain-1 space and began my initial 3dc cluster of the second round with a chain 3, and then proceeded as I had for the first round.
When I finished the second round I joined it to the 3rd chain of the first dc, fastened it off, and wove in all of the ends:

I then turned the hairband upside down an began working around the foundation chain between the 3dc clusters in the opposite direction of the first two rows:

After completing the first 3dc cluster, I chained 1, and then worked the second 3dc cluster between the next two 3dc clusters of the first round.
After completing the 3rd and 4th rounds, I fastened off, wove in the ends, and then added a row of single crochet around the outer edge on both sides of the hairband:

and I think the new hairband works at least a bit better with the poncho to-be:
