For the seaweed poncho, which is somewhat (mostly) my own design, I used generic homespun yarn on size 15 and 19 needles.
Using size 15 needles, CO 59 sts. Do a seed stitch for four rows, or one inch.
Knit one row, then switch to bigger needles.
k1, *yo k2tog*, rep from* until piece measures 10 1/2 or 11 inches.
switch to smaller needles, knit one row.
Seed stitch four rows, bind off loosely.
Repeat this for second piece, block, then sew together, lining the left corner of one piece to the right corner of another piece such that you have a triangle (the book I used as inspiration for the design had a diagram and formula for piecing together ponchos that's pretty basic and universal, though I have trouble explaining it. You can sort of see the seam in my picture).
I did not block this. But I should have. And still should. Especially if it's going to be a gift.