To control those extra stitches, do this..
After your k1, yo, k1, yo... row, purl across the next row. Then k2tog across the next row. Purl across the next, then k1, yo across. Continue these four rows, but at the same time
, increase 1 stitch on each end on all right side rows.
You'll soon end up with a lacy and easy shawl.