I've been making these in my spare time for the last few months. I'm up to 8 now so I have officially switched over from my cut up towel rags. Which is nice. The towel rags were definitely more absorbent but these are much prettier and scrub things surprisingly well. I found the pattern here.
Cast on 4
Knit 2, yarn over, knit across row
Repeat until 40 stitches
Knit 1, knit 2 together, yarn over, knit 2 together, knit to the end of the row
Repeat until 4 stitches left
Bind off and weave in ends
Use size 7 needles with worsted weight cotton yarn. Mine is the Sugar 'n Cream brand.