The fact that smart objects can be duplicated within the same .psd file means you can repeat them over and over to create patterns. I started the design below in Illustrator by creating a single triangle with bits of lettering inside it. Then I pasted that into Photoshop as a smart object and duplicated it loads of times into the pattern below (using the secret kaleidoscope recipe).
Whenever you want to try a new pattern, all you have to do is double-click on the 'vector smart object' in Photoshop and it'll take you to Illustrator where you can edit it. Once you've changed it, just save and close and it'll update the Photoshop file automatically. Lots more time to spend trying new patterns.