Overall, when wearing shorts during the day, it's best to pair them with flats, like Jessica Stam (second from left) did recently in New York. As she is a model, duh, she can wear a shoe with an ankle strap, but those with shorter legs should pick something that elongates their gams. This means anything without the ankle strap, extra points for a nude-colored shoe.
Boots and shorts are usually a bad idea, especially if those boots are black. If you must, follow Alessandra Ambroisia's lead and chose a boot in a tone that's similar to your skin color (so it blends with your leg). Keira gives us some pause. While it's ridiculously way too hot to work tights and shorts in LA, we get that a) she's in London and b) this style is having a bit of moment. Tights aside, we like her proportions. The cropped jacket over longer, loose t-shirt, and body conscious shorts is smashing.
If you really want to wear heels, we suggest that you wait until night (kinda like our advice on mini dresses). Pick a shoe that's simple, yet relatively substantial. This is not the time to wear your favorite strappy, skinny high-heeled sandal-all that foot flesh is vulgar. A peep-toe or little platform is okay, just keep the shape clean, like Mischa did for a dinner at Mr. Chow. Mischa's favorite Louis Vuitton shorts are dressed up with the heels, red lips, and skin-covering cardigan-perfect for after-dark outings.
And finally our favorite, Kate Moss. While normally we see the shortest of shorts on her frame, we like that she picked a classic, black, tailored, dress short for a meal at Cipriani in New York. Again, the proportions she's wearing would be flattering on most people, as Moss offset the length of her white, tucked-in t-shirt with a longer sweater. She's also got on a fantastic pair of platform wedges that are high without being hookerish!
3) Generally it should hit at (or just below) your hip bone
4) Never wear them unzipped and waistband rolled-even at the beach, Heidi.
photo of Jessica Stam, courtesy of Pacific Coast News.