Don’t you just hate it when you are walking and can feel your lining and skirt sliding and twisting around in different directions? It is super irritating, but it can be fixed in a few easy steps..
I make a chain to join the lining to the skirt at the side seams (and maybe front and back seams if you have these, depending on skirt fullness). Easy peasy, and it stops your lining sliding too much – an inch or so is a good length to allow some movement, but not too much.
p.s. for all those keen eyes, yes that is navy thread on a black garment. I did it *cough* deliberately to highlight the specks of blue in the print, and not at all because it looked black when I was sewing in the evening and by the time I noticed it this morning I’d done too much to unpick it all. Deliberate style choice, totally intentional.