If you're new to thrifting, or just scared of it, I urge you to dip your toes into the second-hand pond by starting with sweaters. Chunky funky knitwear is the easiest find and simple to work into your wardrobe. Just throw whatever you score over some tight jeans and you have an effortless look.
This sweater is a favorite of mine, the salt and pepper color gives it a tweed-ish look that is perfect for fall.
Jacket: Urban Outfitters (old, similar here and here)