Forgive me if this tutorial seems to be too basic. My 1950’s playsuit pattern had instructions on how to insert the waistband in a way that required no hand sewing. All of the modern patterns and books I’ve used have you stitch half of the waistband down then slipstitch it in the inside. I find that to be tedious. I don’t mind catch-stitching a hem invisible or tacking down a facing. But when there is no real benefit to all that hand sewing I don’t see the point.
First thing you need to do is press your waistband in half and then press the seam allowance up on one side of it (this will be the front).
Next, flip it inside out and stitch on both ends of your waistband from the fold in the middle up to the fold of the seam allowance . Turn your waistband right side out. Line the unfolded edge up with the inside of your skirt or pant. Stitch, trim the seam allowance, and press up towards the waistband.
Now simply top-stitch the part of the waistband you folded in place and you are done! I think I would only do the slipstitch routine on only the most formal of skirts. Otherwise this is neat, tidy, and fast.