I second Angie’s suggestion to start with a closet edit. That’s what she instructed me to do six years ago when I retired, and Mr. G and I decided to move from a 4-season climate to the PNW—and from a custom-designed house with loads of storage space to a small condo with a bare minimum of closets.
The most instructive part was when I pulled out only the items which I truly loved and knew I wouldn’t let go. That pile on the bed (about 10-15% of my closet) became my new style direction because, for the first time in ages, I could clearly see what I enjoyed wearing. In my case, a “uniform” of boots and flats/jeans and slim-cut pants/sweaters and well-cut mariners. Once I tossed in a couple of well-fitting blazers, a few scarves, a leather jacket, a well-loved duffle coat, a raincoat, and my favorite leather cross-body bag, I had the start of my new closet. I picked out a couple of dressy outfits, some summer outfits with sandals, and a bit of gear—and I had reduced my wardrobe by 80%!
Of course, it does get more complicated once you start going through all the items which are still on their hangers in the closet, especially when they represent a sizable chunk of cash and you are happy to wear the items under certain circumstances. Starting, though, from a drastically culled wardrobe which was full of things I wanted to wear did make it somewhat easier to cast a more critical eye on the bulk of my closet.
The eventual size and composition of your closet will be a work in progress as your lifestyle changes, but it helps to have a core of what you truly like to keep you on track when you aren’t sure of whether or not you might “need” something in the future. In most cases, the answer, for me at least, was “probably not”!
ETA: I also tried to control my “but, if the Queen of England invites me for tea, I might want to wear this...” instincts when evaluating whether or not to get rid of an item. It’s always possible that you might let something go which you later could have worn, but it is more likely those items will just reside in your closet, unworn, for a couple of years. In my case, if I was wavering, I just told myself I could add in a new item if I ever found myself in that specific situation.
I’m still waiting for my invitation to tea...