In this Quick Tip I will show you how to create some dynamic backgrounds by using the effect CC RepeTile, Fractal Noise, and using resources from a website such as Subtle Patterns.
Watch the Screencast
Another useful tutorial to consider is our guide on how to loop your textures for a more dynamic background. It's a different technique, but something that's equally handy to know!
If you're interested in getting some help with your After Effects project, Envato Studio has a great collection of Video After Effects services that you might like to explore. You could also take a look at the After Effects Project Files on Envato Market.