If you take all the items of clothing in your wardrobe and calculate the possible number of combinations (aka outfits) - it's a lot. It's very unlikely that you have considered them all. Don't get me wrong, many of them won't be good, but there might be some gems worth searching for.
This was highlighted to me years ago when I was standing in a crowded corridor of a uni house party, and one of my housemates arrived in my clothes in an outfit I'd never seen before. One I went on to wear myself on other occasions.
She had paired a dress and a top in a way I had never considered, making a whole new outfit.
This stuck with me, but it never quite dawned on me how I could recreate the effect of a fresh pair of eyes.
It felt like some people have a gift for intuitively putting outfits together that the rest of us don't.
But when the algorithm saw fit, it showed me something that completely changed my mind. I've recently started following the Instagram account of Percia Verlin (@Perish). It's essentially a BTS of being a well-dressed person. And it turns out that it takes a lot of thought. A few of her videos show her trying on an item of clothing she's just bought with loads of things she already owns, and she talks through what she likes and doesn't. The point is that combining clothes to make a great outfit isn't always (or ever) divine intuition, although I'm sure you develop that over time; after all it's a skill like anything else you can practice.
There are well-known techniques used by professionals to spark creativity. One is a quick-fire approach of coming up with 10 or 20 (or whatever number you pick) solutions and not being judgemental on whether they are any good. Another technique is actively thinking of some "bad" solutions to your problem.
Although they sound slightly odd, they're both exercises in getting your brain away from its first and most obvious solutions and down a more creative path. You might unexpectedly like one of your initially dismissed ideas, or they might inspire another train of thought. This is much like what Percia was doing. She started with her new item and combined it with lots of other items. It's acknowledging that you won't get the best results if you rely solely on what's in your head.
This method could be applied to clothes you already own, not just when you acquire something new.
When you're picking an outfit, and you get that feeling of 'I don't have anything to wear,' choose one thing you're happy with, a top, a pair of jeans, or a jumper, and work from there. Try on options to go with it that are beyond your initial instincts, remembering that the pros trial and error all kinds of combinations before they're happy.
After all, the most sustainable clothes are the ones we already own.
