I used to have my childrens art displayed in our Georgia home in our Computer/Kid TV room. I LOVED it there. Totally brighted up the space and made it theirs. I didn't have alot of extra wall space to put them in our Texas home. So they sat in a closet until recently - waiting to be put back up.
(Sorry these pictures are so HORRIBLE. By lighting in my house is not that great and I worried that the flash on my phone would bounce off the frames and make it so you couldn't tell what i was taking a picture of.) I found that Dollar Tree had plain flat fronted frames. I bought 5 to begin with to see if I even liked where I was imagining putting them.
I LOVED how they looked. I went out the next day to buy more. My daughter has two great 11x17 peices that HAD to be on the wall - so I had to go and buy 2 frames from Hobby Lobby that were normally $14.99 but I hit them on the right day and they were 50% off. I didn't feel so bad paying for them. I hung them up with the 3M picture hanging velcro like removable tabs that I LOVE so much. I definetly wouldn't have gotten them as straight as I did and as even as I did without them.