When I decorated my older son's room years ago, I had the same issue - holes galore. So, I found The Amazing Monkey Hooks. They have a thin gauge that's inserted into the wall (no stud or tools needed) and makes a single small hole. Gone with the big holes!! They hold up to 50 pounds as well. The other thing I like about them is you can't see them over the top of the picture frame. They are reasonably priced and you can find them at stores like Lowe's and WalMart.
This is what works for me. To see what works for others, visit Rocks In My Dryer’s Works for Me Wednesday. You might find something that will work for you too!