Bed skirts are alive and well. It just depends on whether your bed requires one of not. If you can see your box springs under the coverlet, then you need a dust skirt, which more often than not these days is a tailored one, not ruffled.

Your sheet color has little to do with your dust skirt. It needs to go with the coverlet or quilt or duvet you have on your bed. It CAN be white, but does not NEED to be white. I'd pick a color from the coverlet for the dust skirt color.
Carolyn Albert-Kincl, ASID

If you have an bed that makes a statement the dust ruffles should not be used. For example I used the parts of an antique english back bar to build a queen size bed whose effect would have been killed by not seeing the construction.

When I was looking for a clean look in my daughter's room, I purchased a navy blue fitted sheet and put in on the box spring. So, I didn't have to see the box spring fabric pattern and she didn't have anythiing hiding the space under the bed. That worked to keep the under bed space available for storage crates, but not a catchall for dirty laundry, school papers, etc

Linda, that's an excellent solution to the problem. And Custom, I agree that if you have beautiful wood sideboards that cover the box spring, you should not use a duster.

You can use a dust skirt with side rails...simply velcro to the inside of the rails. :)

I like to omit the dust skirt unless it's absolutely necessary, for a more open, modern look.