Once you have your new "stitches" in place it's time to bind off. You'll keep your ribbing in pattern regardless of whether you were working knit 1, purl 1 or knit 2 purl 2. This bind off is basically the standard bind off with a little difference.
Since I was working with knit 2, purl 2 ribbing, I knit the first two stitches and passed the first stitch over the second as usual. I then slipped the make 1 as if to purl and passed the stitch on the right hand needle over the make 1.
To continue, I purled and passed the make 1 over, purled again and passed the stitch over, slipped the make 1 as before and so on around the bind off.
For a knit 1, purl 1 rib you would do the same, just knitting and purling respectively and slipping the make 1s as you come to them.
Not actually working those make 1s means you're just adding a little extra yarn to your bind off, which gives you more room to stretch in.