Because I have way too many clothes twice a year, spring and fall, I go through my closets and shift. Typically I just move my out of season clothes into the guest room closet, and I move my in season stuff into our bedroom closet. But before I hang in the closet or place in the dresser my in season clothes, I cull.
My method isn't quite as organized as this, but it's close. Here's a method the National Cleaners Association suggests:
Start with 5 good sized boxes and label them - keep, donate, dump, fix, maybe.
Keep - Start with jackets, suits, and separates. Inspect them carefully for wear and tear. Keep your essentials as long as they are in good condition, still fit, and don't look dated.
Donate - If you're the same size and haven't worn something in a year or more, plan to give it away -- unless it's evening wear. Those items have a longer shelf life.
Dump - Throw out clothes that aren't fit to donate. Keep a few things for dirty jobs like gardening and painting.
Fix - Inspect everything carefully. Put anything that needs a hem, button, alteration, or cleaning in this box. Go through it twice to make sure you want to make the investment in it.
Maybe - This box is for the item you got on sale but never wore because you don't have anything to go with it or it's just a touch too tight. Seal this box and put it somewhere away from your closet. Anything you don't miss after 4 months should be given away.