The situation:
I have a messy folder with a few hundred subfolders and a few hundred files and no idea how to structure them better. 
The folders are sorted at the top before the files and the files below are usually sorted by last modified time, sometimes by name and rarely by type.
The problem:
My mouse is getting a workout and even with Logitech’s “Hyper-Fast Scrolling Wheel”, it’s often annoying to scroll all the way down and up to the newest file or folder.
One idea:
I would welcome keyboard shortcuts like Shift + ← and Shift + → (seems to be unused at the moment) to jump directly or back and forth to the next from [first folder, last folder, first file, last file] or just [first folder, first file].