I know. Not exactly what you want to hear. My first suggestion in this series on a better wardrobe was buy a mirror. Pretty simple, right? And now I'm merely suggesting that you clean up your closet. Not clear it out. So what do I mean by clean it up?
Pick up anything thrown on the floor.
Hang clothes that should be hanging on the rack instead of strewn across a chair.
Get rid of the lingering clothing mounds on your shelves. Fold all sweaters, jeans, and t-shirts neatly.