This database was created for the GDC Talk “How (not) to create Textures for VFX” (recording & extras here) and contains many links to tutorials, texture/brush packs and photo/video footage to help you to create nice VFX textures.
Click here for the 3 options on how to browse the database:
Click one of these categories to get a nice overview with thumbnails:
A few picks which I found especially awesome.
Here you find the complete database with all resources.