These are the choices I suggest for a 3/1 top edging:
1) start out with a 1/1 setup, knit 1 row, do the selvedge rows (2 rows with the ribber out of work), then knit 1 row. Then convert over to a 3/1 ribbing and knit the rest of the sock.
2) start with all cylinder stitches (no ribber) and an e-wrap selvedge; knit 1 row, then convert to a 3/1 setup and knit the rest of the sock. (you'll find information on e-wrap selvedges here: http://www.yrstation.com/pdf/Home%20Study%20Lesson%20Three-a.pdf)
3) start with all cylinder stitches (no ribber), knit 2 rows, hang the first row (for a very short hem-top) on the needles, knit 1 row, then convert to a 3/1 setup and knit the rest of the sock.
Personally, I usually use solution 1, but I knit at least 10-15 rows of 1/1 ribbing at the top of the sock before converting to a 3/1 leg.
(posted by me this day on sockknittingmachines)
