with a top down - you won't even need a pattern!
i do my baby hats by casting on eight stitches over 4 dpns (knit with the 5th)
Round 1: knit even
Round 2: kfb every stitch (16 stitches total, 4 per needle)
Round 3: knit even
Round 4: (do this on every needle) kfb, k2, kfb (24 stitches total)
Round 5: knit even
Round 6: (do this on every needle) kfb, knit to last stitch, kfb (32 stitches total)
Repeat round 5&6 until you've got the right circumference. Then just knit even until it's long enough and you're done!
(Of course, just change it to k1, p1 for ribbing, or you could do the increase in stockinette then start ribbing.)
Does that make sense?