Do you hand knit?
Create knit and purl stitches by hand
Alternative to Hand Manipulation: Mock Ribbing
"Ribbing" with Tuck
Hat Inspiration
Knit Club Replays: Ribbing

A "mock" rib variation

For the look of 2x1 ribbing, without hand manipulation or a ribber, try tuck!

This stitch pattern doesn't pull in or stretch like regular ribbing but it does produce columns of stitches that resemble ribbing.

Remember tuck knits wider than stockinette, so you may want to cast on fewer stitches than your garment piece, knit the "ribbing", then cast on some stitches for the garment width.

This also requires weight (add more weight than you would plain knitting). Because there are loops over 2 needles, you want the weight to control those strands so they don't loop over the gate pegs of your machine.