frequently notes that if you do not use an item for a year, clear it from the wardrobe. I have a related, but methodologically different, approach: know how much of your wardrobe you use and, for pieces unused, consider how you can use them. If you just dislike them, then definitely get rid of them. These are my data and this helps me review every week how I am doing. Overall, I am happy with the use metrics and attribute some of this to my insisting Tuesdays and Fridays use infrequently used items.
The big category atop the list includes dress shirts, short sleeve shirts, long-sleeve casual shirts, and jerseys. It's my biggest gap area, largely because I have a lot short sleeve shirts not worn since last summer.