I have two sizes, small gold ones and large silver ones. They are different from safety pins, because there’s no loop at the bottom.
I use them to mark groups of stitches as I cast on. (I only use circular needles, so even the small ones fit over the cables.)
Instructions for ribbing and seed stitch can get very cumbersome, depending on whether they’re worked on an even or odd number of stitches. (See the possibilities at the bottom of the post.)
But working these fabrics, without reference to instructions at all, can be very easy once we understand how the fabrics are constructed. I’m not saying we memorize the instructions. Instead, we understand the underlying theory of how the fabrics are formed.
When we bind off a project, we should almost always bind off “in pattern.” That means that as we work our way across the bind-off row, we work each stitch as though we are working the current pattern row.