All my notes go into Notational Velocity. It's super fast to take notes, search through my notes, and it keeps everything in one place.

All my assets go into a project folder in Dropbox.

It's a very quick "not spending time organizing" kind of system so I can focus more on the doing.

All notes in Evernote, all files in Dropbox.

A mixture of paper, macOS Notes app, Evernote, and OmmWriter+Scrivener synced through Sync (privacy-aware Dropbox alternative) in case I do morning writing sessions (brain dump).

I use Notion.so for all documents and Dropbox for files.

I use nvALT (fork of Notational Velocity mentioned by @jillbinder) for my text notes. It's great and very fast. brettterpstra.com/projects/nv…

I occasionally use iCloud-synced Notes.app for things that I need on-the-go and synced immediately. (I also use Dropbox to sync my nvALT text files but I still haven't found an iOS app I like for it).

Design inspiration images/video I store in Pixave, although I don't use it a ton. www.littlehj.com

Other than that I don't store many random snippets.