You can make ponchos in different shapes. I started knitting the poncho above from collar. With increasings, it has become a triangle shaped one.
How I made:
I started with 100 loops. I have knitted 2 plain, 2 purl rib. When rib knitting become 5 cm. I knitted 1 row of garter stitch. (To turn the collar) I knitted 5 cm. more. I made holes for the cord by taking 2 loops together and winding cast on 1. The next row, I passed yarn to 50 loops and got it waited.
I knitted 21 of the other 50 loops plain knitting, 1 winding, 1 knitting, 6 loops set for cable knitting, 1 winding, plain knitting of 21 loops. When I passed to the back side, I had 52 loops on the needle. I knitted the back side the same way without increasing.
On the front side, I knitted 22 loops of plain knitting, 1 winding 1 knitting, every 6 rows I made 1 cable knitting turn. 1 winding 22 loops of plain knitting. Now I had 54 loops on my needle…
Until I came to the length I wished, every front row, I repeated these increasings. At every 6 rows, 5 loops from inner both sides. I casted off at one row. I knitted the waiting loops the same way.
Now we have a poncho. You can adorn yours with different variations. With darker or lighter colors of yarns. You can add fringes. Instead of plain knitting, you can prefer to use garter stitch technique etc. You can make lines while knitting. You can add pockets… Use your inspiration….