There are several great references on the web for dealing with steeks. See Knit a Norgi by Geane, or Wendy's Tips on Fair Isle and Norwegian steeks, or Flor's page for excellent photos and help.  But if you don't have a sewing machine, you'll definitely want to know how to work a crocheted steek.

Crocheted steeks are described best by Meg Swansen, in her books Sweaters From Camp, and in Meg Swansen's Knitting, available from Schoolhouse Press . Both have illustrations in black and white on how to chain-up the left and right halves of a stitch, along with some additional refinements. Here are the results of my crocheted steek experience, and I'm very happy with the method. Grab a crochet hook and give it a try on your next steeked project.

Mimbres steeks (right down the middle and at the sides) with my dachshund, Little Jack. The Mimbres Vest was designed by Meg Swansen and can be found in her book:
Meg Swansen's Knitting.

Here is my steek, seven stitches wide and straight up the middle. It's speckled, but you could stripe, too. Of these seven steek stitches, I'm only going to work on the three center stitches. Imagine them as six half-stitches, as per Meg Swansen's advice.

I began by crocheting a little  chain, then I crocheted up half of one turquoise stitch and half of one brown stitch (two of the six half-stitches). I crocheted to the top of the steek, then shifted over to the adjacent two half-stitches, and continued crocheting down to the bottom of the steek.

The two crocheted chains on the steek looked like this (the image on the left) when I was finished.

Between the chains is a little ladder of stitches. The ladders are the stitches to cut. Be careful and don't cut the crochet chain.

Because I was nervous about this process, I used a seven-stitch steek. You can see what a nice narrow facing it makes in the image of the armhole steek on the right. However, if you wanted a narrower facing, you could work the steek as Meg Swansen does, on five stitches, or even three!