Making my phone's home screen functional. Calendar widget on the left, notes widget on the right, 3 rows of frequently-used apps on the bottom.
Went from having no calendar nor a quick place to jot notes, to having a severely overengineered planner with built-in notes that I didn't actually use and didn't fit in my pockets, to now finally having my day organized and my mind clear.
Also centralizing my random notes into a single ~/Documents/quicknotes plain text document for each of my machines with a taskbar shortcut pointing to it.