I have gone from being a naturally untidy horder to being a tidier person with a lot less stuff, in a cleaner and bigger house. It helped that we movwd house a few times and I had to make decisions about things.
Having lots of good storage helps. I also decided some years back that I prefer photos on the walls to rwmember people over clutter or memorabilia so I got all the surfaces clear and just have the odd clock, candle or vase of flowers.
I still hoard a lot of different craft supplies, at this stage in case DCs will want to use them, mostly, but also in case I need/want to make something.
Then I have worked as a cleaner on and off and so have learned how to get a whole (uncluttered) house clean and sparkling in a matter of hours, and this is motivation to keep the clutter at least in unseen corners and behind screens and not on constant display to everyone, making cleaning difficult.
I've been pretty goid for a year or two but am seeing clutter accumulating again, and in my head I haven't any idea of what to do with it, as I have so much on my mind and sorting is such a bore and chore.
So clearing your head of negative thoughts or persistent distractions is a way to change one's natural inclinations, I think. Looks as though I need to work on this myself too. :)