The perfect little casual polkadotted dress, easily translated into fall by wearing it with a long cardi and a trenchcoat. Keeping the warmer layers on top allows you to keep the legs more summer-appropriate, without socks and with open shoes.
source: The Stylish Wanderer
I really want menswear inspired pants that have narrow enough legs to be cuffed, but are loose enough not to feel clingy and sweaty when the temperatures do suddenly rise a bit or when the sun decides to come out and play. These would be perfect, and I would wear one of my bustiertops underneath the blouse to up the versatility of the look: shed the blouse to handle unexpected heat!
wearing summer's skirts and shorts with fall's sweaters and boots - but without tights - keeps you warm when mornings and evenings are cool, but your bare legs still give you a bit of a summer feeling. Especially when they're tan and when your sweater and boots have colors not typically associated with fall. Take a bright colored or white sweater and use tan boots instead of blacks or fallcolors to keep the look fresh.
wear a light, preferably seethrough skirt of a slightly longer length over your minidresses to keep your legs warmer. The peek-a-boo effect keeps the look fun and summery!
if you wear a flower crown in your hair, ANY outfit will get a slice of summer injected into it. Parkas and knit sweaters will instantly look ready for a watery Belgian summer when you wear those hippie adornments on your head!