Probably my number one addiction when it comes to scrapbooking is patterned paper. Many friends have expressed to me that they are a little 'scared' of using a lot of pattern, however, especially when it comes to mixing them. I want to suggest that a great way to use fun, vivid patterns in any combination is simply to use them sparingly and against a very neutral background.
Here are two examples. In this first one I used thin strips of multi-colored paper as a frame around the white background. With all the quite-literal white space, I was able to use a variety of coordinating alphas for my title without overwhelming the viewer's eye, adding a touch of fun without detracting from the photos.
In this next layout, the background is actually a very pale blue. Although the patterned papers are very bright and all different, they are again present in small amounts. The patterns themselves are small as well. The placement of the papers leads the eye to the photos, and the paper in the circle serves to tie the colors together. The brightly-c0lored lines it contains are so very thin that they are hardly noticeable themselves; it is a very subtle pattern.
I would love to see (and share!) your examples as well!