The challenge was to knit a swatch in the round, then to steek it. I picked a mohair/wool blend out of my stash because it seemed very "sticky" to me (all those mohair hairs poking out all over the place), and because I conveniently already owned it in two colours, and I guessed and picked up some 3.5 mm needles. For fun, I did a two-colour long-tail cast-on, which I've never done before, and made up a simple colourwork sampler pattern as I went along. Then I did a two-colour suspended bind-off (link shows the bind-off in only one colour; for the two-colour bind-off you just alternate making stitches with each of the two colours of yarn), which I didn't like as much as the cast-on. The CO edge looks really neat and tight, and you can clearly see the two colours, while the BO edge is a bit floppy and flares out. Each stitch is a little bit too big, so it might just be a matter of using a smaller needle to bind off, or maybe doing a bind-off that's less elastic than the suspended bind-off.
Then, following Kate Davies' excellent instructions, I crocheted a reinforcement with some smooth sock yarn (also stash) and a 2.5 mm crochet hook. I did struggle a little at first because I couldn't figure out how to hold the swatch and crochet comfortably into a column of stitches, but then I pinched the swatch so that the column I needed was at the top edge (basically mimicking the way you would crochet into a row or edge) and it became a lot easier. When I compared my work to Kate's, I noticed that I didn't crochet over the CO or BO edges, whereas she did, but since this is my first steek and just a swatch, I decided to just cut it and see what happens.
Then came the moment of truth...cutting time! The crocheted reinforcements really nicely pull the stitches apart, so that you can see exactly where to cut, and a glass of wine really nicely takes the edge of the fear, so you can pick up the scissors and start cutting.
This really did help ease some of the nervous feelings I had about steeking, because I can see how the crocheted reinforcement really has your back and holds everything in, so that it looks nice and neat from either side. As well as learning a few new skills, knitting with these two yarns from my stash gave me some great ideas for designs, which is an awesome bonus. All told, a worthwhile exercise!