Expectations: “I’m going to frolic through the fall leaves in my riding boots with Pumpkin Spice Latte in hand as a cool breeze blows through my hair.”
Reality: “It’s going to be 100 degrees out today so the riding boots and sweater will last for an hour tops before I’m forced to change or risk dying of heat stroke.”
First, I’d suggest you take a look through the clothing tag. I think there are some references for how to describe clothing in there.
Second, think about how the fabric itself. Does it billow behind your character when they walk? Does it make a swish, crinkle, or other sound? Maybe, if it’s leather or suede, it has a unique scent? Does it shimmer or sparkle? Does it have a pattern? Is it scratchy or soft?
Then, think about what garment it is? Is it a blouse, or a pair of trousers?
You may find it helpful to search of Tumblr for the ‘fashion’ or maybe look at a magazine like Vogue or Bazaar to hear how people who work in the fashion industry describe clothes.