1. Out-of-sight, out-of-mind method
Put the items that you wear the least in a plastic bag, bin or box. Place it in the back of your closet (out of sight!). If you remember or miss an item you can put it back into your closet. The items that haven't even crossed your minds after a few months are ready for a new owner.
2. The ribbon method
Tie a ribbon around your closet rod on one side. Next step, move all your other clothes to the other side. The items you've worn should be placed on the clear side of the ribbon. Over time this method will clearly seperate your favorite items from the one you never wear.
3. Set-number-of-hangers method
This is method is probably not for everyone. But if you really want a pared-down closet, you should limit it to a certain number of hangers. When you run out of hangers you have to throw out some items to make room for new pieces.
4. The tag method
Try not to get too excited after getting home from a big shopping spree. Leave the tags on until you actually wear the item. Next time you clean your closet, it is easier to see if you have actually worn your new items. If it's been several months since the purchase date and you still have the tags on it's better to find a new owner for these pieces.
5. One-in-one-out method
As the name of this method already explains, whenever you bring home a new piece, you have to take one out. That perfect suede Gucci jacket will replace that old blazer you never wear and so on. It's a pretty strict method but it's very effective and will make sure that your closet is never overflowing.