Now, don’t get stressed out: This isn’t an I.Q. test or anything, but take a second to look at the shapes below. Which one seems, how shall we say this, more streamlined?

The blue one on the right, right? That’s what I think too. Today, this elementary school exercise came to mind as I walked by a major retailer (who shall not be named) whose store windows were filled with dozens of these knee-length skirts:

Now, to the untrained shopper’s eye, these breezy pieces may seem a comfy summer classic, but to a savvy sartorialist, they scream UNFLATTERING. Tapering at the waist and breathing out at the calf, the skirt emphasizes the widest part of the lower leg: the hard-to-miss calf. Even with a sleek top, this leg-heavy silhouette makes the wearer seem short and stumpy, adjectives few find appealing.

To avoid such wardrobe pitfalls, try this simple styling trick: To figure out if a potential purchase will be flattering or not, try to zone in on the silhouette by thinking of every garment as a square, rectangle, diamond, or circle. (This I learned from a fantastic ballet teacher who instructed her students to think of their bodies as wooden blocks, and to think of every ballet pose as aligning the blocks in a particular composition. The concept works just as well when applied to body parts and wardrobe pieces.)

Here, an example of some of the most slimming warm-weather silhouettes:

*Snaps= 4 silhouette examples from Victoria’s Secret