Here in the South, Autumn doesn't really begin until late October/early November where temperatures are concerned. It's the middle of September and it's still 80+ degrees Farenheit regularly, except for the occasional cool day (cool being 70 degrees).
Nontheless, as it is Autumn in my mind, I'm about ready to encorporate the styles.
In order to not melt, I encorporated two monochrome pieces: one striped, one with a geometric pattern, both flowy and lightweight (skater skirts are miraculous). I didn't want to do anything to colorful but to keep a clean palette, not only so the accents would truly pop, but also because I was mixing patterns. The best and most effective way to mix patterns is within the same color scheme, or better monochromatic: simple, yet not.
For accents, I went entirely berry: Revlon Colorstay Moisture Stain in the shade "Parisian Passion" on the lips & Rimmel 60-Second Rita Ora nail color in "Rita Rouge" on the nails for a shot of Autumnal sophistication.
What are you wearing as the Autumn season creeps in?