The fabric is very important, look for a soft jersey that has stretch, drape, and lightweight. Basically soft tshirt fabric.
Measure from the side of your hip to all the way around to the other side of your hip and add 1 inch. This is the measurement for the width of the main skirt piece.
You will have 3 pattern pieces. The main one will measure your above measurement by 33 inches long.
Their will be 2 smaller pieces both measuring 36 x 8inches.
If you want finished edges you will want to do that to all the pieces before beginning below. Add 1/4 inch seam allowance.
Gather both sides of the main piece, I've done this enough by now I'm sure you all know. Basically scrunch the fabric creating pleats. Make sure to get good pleats, you will want it to go from 33in. to about 8 inches at the end.
Repeat the gathering on both sides. Once finished, take your other 2 pattern pieces and pin or place to each gathered edge.
Sew right sides together on both sides.
It will look like this when done on both sides.
Simply wrap the skirt around your waist. You can tie the straps and hide them in the back or wrap around to the front...play around and see how you like. Hide the tie under your shirt or even create a bow for the back or front.