i love, love, love paper! it is my favorite scrapbooking supply to buy and i have tons! and sometimes the paper i want to use for a project isn't quite the right tone or texture so i alter it. there are some fun and easy ways to alter paper like sanding, whitewashing and inking.
whitewashing: water down some acrylic paint (white or any color really), paint your patterned paper and let dry. make sure to work on a non-stick craft mat or your paper might stick to your desk as it dries (i speak from personal experience, my poor desk). your paper won't be quite as flat as when you started but you can iron it with a craft iron or flatten for a bit under a book. or i just use a little bit extra adhesive.
inking: ink up a brayer and roll over paper. add layers until you which the desired result. or try another way to get the ink to the paper like make-up sponges, plastic wrap, bubble wrap, etc.
and here's another card i made, that green floral paper was a screaming lime green when i started. and once i started whitewashing, i got really into it! i raided my scrap drawer and whitewashed a ton of patterned paper!