Step 1: How Simple Is This?
About two yards of stretchy fabric like a jersey knit. This fabric will probably come in widths of 54: or 62 inches, either is fine
Something to measure with is also helpful.
Step 2: Lay Out Fabric For Cutting
Step 3: Measure and Cut
Step 4: Wear Your Cardigan!
If you want to wear it in even more ways and you are feeling ambitious, you can sew snaps to the corners, but you can wear it in tons of ways without doing that.