The Maxi Skirt. While maxi skirts are perfect to wear for summer, they are thee winter skirt. You get the chicness of a skirt but with the benefits of coverage. The best way to take a maxi skirt into fall is to add a great jacket. Military, leather, even a blazer would look great. Make sure to pick something whose fit complements the length of the skirt, don't pick anything too long or bulky because all the fabric might overwhelm your body. Cropped, tailored jackets are perfect. Also, to combat those chilly breezes, add tights underneath with some boots or wedges.
The Sundress. I live in dresses during the summer and I don't want to give them up just because of a change in weather. Luckily, adding just a few pieces to a sundress instantly takes you from summer to fall, and adds interest and dimension to your outfit. Trade in your sandals for boots (cowboy, motorcycle, ankle, thigh high-- your choice!) and throw on a leather jacket. I love the juxtaposition of tailored jacket over a flowy feminine dress. Tres chic!
The Gingham Shirt. Of course, it doesn't have to be a gingham shirt, any button-up will work perfectly. Button-up shirts are ideal for layering and create the perfect starting point to a fall outfit. Here I threw a pull over sweater on top of the button-up, not only do I get that extra layer of warmth, but I also add interest to a plain pull-over by pairing it with a patterned shirt. Practical AND stylish, who can argue with that? Throw on some skinny jeans and oxfords and you have a perfect casual fall outfit.
So there's a few ideas on how to tweak your pieces from summer and get them to work for you during the fall. Hopefully it helps you transition a bit easier. If you have any of your own ways of changing up your outfits, I'd love to hear them!