One thing that kept occupying my mental space were the papers and notes that I wrote. I carried a notebook with me and wrote all my ideas in it.
I thought it was better to have it online than on my physical notebook. Physical notebooks are not possible to carry everywhere and there's a chance that it'll be damaged in the future. So, it's not future-proof either.
I thought of scanning those papers and keeping it online so that I can access it whenever I want.
Upon researching for sometime, I came across apps which does that pretty easily whether you're on ios or android.
The app I use is Scannable. I scan every paper and then it gets automatically saved on Evernote with the tag "Scannable". It has made my life so easier. No papers to deal with and no stuff to organize physically. Becoming paper free has been helping me regain my mental space.
Try for yourself and see the difference it makes.