First, look at what you have hanging in your closet. Take down anything that you haven’t worn for a couple of years. Its time to make a decision about this garment. Is it out of style? Does it fit? Did you just forget about it? Decide if you want to keep it or not. If not, put it in a trash bag to give to charity, or throw it away if it has holes or stains. Sometimes its easier to part with things if you keep in mind that someone else CAN and WILL make good use of it.
After going through all the things that are hanging up, its time now to look at the folded items that might be on shelves. Take everything off the shelf and put it on the floor or on the bed. Again, look through each item and decide if you can part with it or not.
Look in the boxes you might have in your closet. Start putting off season items in a box to store on the shelf or in the corner on the floor. If you have been storing other things in your closet as well, you ought to try to find a new home for them. Try to just keep clothing in your closet.
You probably have a bunch of shoes and other things on the floor. Take everything out so that you can vacuum completely. There will be lots of dust. Take out the off season shoes, and put them in a sturdy shopping bag or box. Purchasing a shoe organizer of some kind probably would be a good idea.
Now, you probably have bags and bags of clothing that is still in good shape, but you just don’t want it or need it. Its time to bring them to your local Goodwill or other charity organization. Some of them will even pick up your items at your house.