Mid-length skirts, commonly known as midi skirts, are enjoying a fashion renaissance right now.

You might think of your second grade teacher when you consider skirts this length, but as you can see from the shot at your left, featured in Nordstrom's September catalog, it's come a long way since then -- and some of Hollywood's hottest young celebrities are rocking the look on a regular basis.

Still, you do have to be careful with this length -- if worn the wrong way, a midi skirt can look matronly, even on a supermodel.

Fortunately, I'm here to help!

Check out a few great ideas on how to make this look work, whether you're in your 20s, 30s, or 40s -- and see some affordable midi skirts you can score for yourself -- after the jump.

I love Saks Fifth Avenue's advice on how to wear this MARC by Marc Jacobs printed skirt. This particular skirt is more than $400, but these looks would work with any skirt of this length.

In your 20s, keep the look a little more eclectic, like the model in this Anthropologie shot. The bold crop top gives some unexpectedness to this gorgeous Sashed Sweater Skirt (Anthropologie, $148).

In your 30s, use up-to-the-minute accessories to keep your midi from looking too conservative. A leopard print scarf and unexpected shoes keep this 2-in-1 Sweater Dress (White House Black Market, $168) from being boring.

In your 40s, pair a bright skirt with a more conservative top for maximum impact. I'm loving how White House Black Market styled this Flowing Leopard Print Skirt ($88).

Will you dare to wear a midi skirt this fall?

Images (top to bottom): Nordstrom, Saks Fifth Avenue, Anthropologie, White House Black Market, White House Black Market