I don't believe in most fashion "rules." (This is perhaps why I will often show up in a ballgown on a Tuesday morning...I wear what I'm in the mood for, and rarely take the time of year or weather into consideration.) However, many people do like to have certain rules to follow in order to best make wardrobe decisions. One such rule is the whole no-white-after-Labor-Day ridiculousness. As long as it is still warm out, and as long as the fabric you choose is appropriate, I always, always, always continue to wear white throughout the entire year.
Now, how do I manage that without looking like an escaped mental patient? Think white wool, white denim, or white fur. Just use them as the either the accent of an outfit or the focal point. Either way, pair the white piece with everything else "appropriate"...other heavy fabrics but in dark colors, light fabrics in dark colors, etc, etc. Think about a pair of skinny white jeans this coming winter (in a heavy denim) worn with a black turtleneck sweater, black knee-high boots, and an oxblood wool coat. Totally gorgeous and chic.
And what about now-ish, when it is immediately after Labor Day and still warm out...but you don't want to look like you just came from the beach...or are secretly freezing in your little white sundress? At this time, it's all about silhouette and accessories. Try a mini dress that has 3/4 or long sleeves. Or wear a maxi skirt with a dark top. And finish either of those off with Fall-appropriate open-toe booties and earthy jewelry. Wear dark lipstick and choose a suede mini cross-body bag. And voila...white in the fall, done exactly the right way. And this dress, the "Dosa" from Dolce Vita, is a perfect example. It's floaty fabric is still lightweight enough to keep you cool in Indian summer temperatures, but the 3/4 sleeves say "I'm ready for Fall." Combined with printed booties and some rocker-chick jewelry (try throwing in some studded or snake-motif pieces), this is the ultimately chic, fashion-editor look for September.