I saw this youtube short on adding a "slit" to an otherwise boring skirt:
Click to view
It's okay. There's nothing wrong with the lady's instructions--so far as they went. Problem is, us older folks and most of the plus-size's are probably not going to want to wear a skirt with a slit in it like that, so what to do?
Well, here's what I would do:
I'd add a panel directly behind the slit. Made with a lace top layer and a bottom layer in a contrasting color, everyone gets to enjoy the fun of wearing a skirt with a slit in it without somebody snickering about it being "inappropriate".
But why stop there? If one slit is fun, the more the merrier, right?
The key here is to make a blouse the same length as the skirt and then wear the skirt over the bottom part of the blouse (lets it act as a slip). Then, every time you move, you see the blouse color through the skirt slits.
Heck, you might even want to make TWO!