I love coil-less safety pins for marking my crochet stitches but sometimes I don’t have one at hand. This happened to me the other day while I was waiting to pick my husband up at the train. I was crocheting a crochet cat toy for my foster kittens and wanted a way to mark the start of round so I didn’t need to count. While I believe there was one somewhere in the car (I have emergency yarn & needles/hooks stashed away) it was easier to just loop some of the yarn tail into my work to quickly mark the spot.
I’ve found this method works better with a variegated or striped yarn so there is contrast to where I add the marker and it’s apparent in the fabric.
There are several different kinds of markers available and several years ago Lindsey of Poetry in Yarn wrote a nice description ones commonly found. Round ring markers don’t work well in crochet unless you are trying to purposely add rings to your fabric!
There are many different ways stitch markers can be useful in your crochet, from marking where you’ve started (or ended) to counting rounds or rows. Stacey of FreshStitches wrote about how to use a stitch marker for amigurumi and offers clear illustration how to use them.
Looking for more crochet tips? This is a great article from Vogue Knitting (Crochet 2014).