We have a large wall space that is by our stairs. It always drove me nuts to have that much empty wall space, so I decided to do a picture collage like I saw in a Pottery Barn magazine. Everything is monochromatic. Most of the frames came from IKEA though because I like IKEA prices better than PB pricing!
I arranged the pictures on the ground to get a good idea how I'd like them to be arranged. Then my sweet hubby hung them all for me while I watched and told him to slightly adjust things. It looks great and was inexpensive.