This is dead easy and doesn't need a pattern. But you need to wear your top over the waist, or a big sash or something, for reasons that will become obvious!
I made this out of two metres of 115cm wide rayon blend that I got from Spotlight. Two metres makes a longish skirt on an average-height person and you can obviously tweak this. The width of the fabric determines the amount of wrap over.
Cut in half, align the two pieces so that the pattern or nap runs the run way, then sew together (with the the right side inside, obviously). Finish your seams in your usual way. I don't have an overlocker (serger) so I sew a normal straight seam, sew another one about 1/4 inch away inside the seam line, trim close to this and do a closish zig-zag over the cut edge. An overlocker would be MUCH faster.
Make a small hem at the top and the bottom - you aren't going to thread elastic through the top so it can be as narrow as you like.
Put on your person and use a couple of safety pins to wrap and pin the excess fabric around your waist so that it falls like this. (Hence the need to cover the waistline with clothing as it does not look too flash!
It took me about an hour of sewing, I think, but over several hours interspersed with usual domestic and school holiday stuff.
This gives you an easy asymmetrical skirt (I like asymmetry) that fits anyone and, importanly in my case, can be adjusted easily as I lose more weight.
The rayon blend drapes beautifully. The skirt will look different depending on the drape of your fabric - stiffer and thicker fabrics still look good, it will make good winter skirts too to be worn with tights - and obviously you can have it shorter if you wish. I am just about to experiment with a much shorter one to be worn with black leggings. (If I am brave enough - it is YEARS since I wore any sort of short skirt!)
I didn't invent this, or even unvent it - I was told how to do it by someone else, but I don't think it was her original idea either.
The safety pins need a bit of fiddling at first, to get the position right, but then no-one would be able to tell that you are held together with them!