Diagonal with a neat edge made by ncreasing and decreasing on 2nd stitch in from side

I didn't take picture of the steps as this builds on what was done previously.

Increase by crocheting 2 half double crochet (hdc) into one stitch.
Decrease by crocheting 1 hdc by pulling up loops from 2 lower stitches.

I crocheted in the back loops to make ribbed variation. It also makes it easy to count the rows. I used my favorite workhorse stitch, the half double crochet (hdc, european symbol looks like a non serif T )

Chain 9 not including loop on hook. (This always messes me up. I think the standard procedure is not to include the loop on the end when you are counting the chains.)

Rows:

1. hdc, hdc increase, 3 hdc, hdc decrease, hdc
2. hdc, hdc decrease, 3 hdc, hdc increase, hdc

Just keep repeating rows 1 and 2.