Accessories have by far always been my favorite thing in the world of fashion.  Simple shirts and pants can be spiced/switched up with a hat, scarf, shoes, or by adding jewelry.  This time of year is perfect for breaking in your new pair of boots.  Add some gold accessories and they will pop against all things autumn.  Next, throw on your favorite knit, slouchy hat.  My favorite is this cream colored one I ordered on Etsy ages ago.  Don't forget your cozy scarf if it's a really cool morning.  It pulls things together and keeps you oh so warm.  Another fall favorite of mine is dark polish.  Try black if you're daring enough.  I LOVE it. It looks chic, modern, and pulled together.  If that's too much for you, there are many browns, taupes or plums, like this polish by Essie, called Wicked.