There are two ways to declutter.
The first is to be more organized. Find a place for everything, and make sure you put it where it goes.
The second is to have less stuff.
If you employ both of these strategies together, you have a superpower.
This concept is why the ability to focus is so important. More ideas, just like more stuff, can make you feel secure, but it's a false sense of security.
It's better to choose what's valuable, what can help you get to where you want to go and get rid of everything else.
Less stuff equals less mess.