My challenge is about challenging yourself to use as many patterned papers as you can. My rule of thumb when using lots of patterns is to start with a multi-colour paper that I use as the inspiration source for all the colours I pick. Then, the rest of my papers tend to be more tone-on-tone pulled from the colours in the original piece. I find this helps keep it from getting TOO busy :)
Here is my layout (see video below) that I used NINE different patterned papers on! Crazy, hey?! But I think it works. I am not 100% sure on those large Thickers for "Little" but really wanted to use then and... once they are glued.. they are glued!
And here is a second layout that I did recently that also has as many patterned on it. But for this one I used a cut file background so each of the papers is used in a very small amount.