She had already sewn the sides together, so I don't have much of a tutorial for you, but I'll try to tell you how I did it. The skirt was a little long for me, and there was no waistband yet, so I cut off a couple of strips from the top, like so:
Then I sewed those 2 strips together (longwise) - then that seam sits at the top of the waistband. One strip shows on the outside and one strip shows on the inside of the skirt, like facing. Hope that makes sense. I made the waistband smaller than the skirt, so I gathered the skirt part and attached it to the waistband - here's that picture:
I was sure to leave a button on the edge of the waistband - - that's how this skirt comes on and off:
I think it looks cute paired with a color-pop belt:
When my friend was trying to make it fit herself, she added in this side panel (from the sleeves of the shirt) - I love that diagonal stitching detail where she pieced some fabric together:
So if you're looking for a quick sewing project for yourself, try converting a men's shirt into a skirt - you can do it!!