One of the easiest ways to make a wall look classier is to simply put pictures you already have into a grouping. Groupings are an attractive way to hang pictures, and they can very quickly enhance the look of your walls without spending a dime.
There are a few different methods for grouping pictures. When I have done groupings, I just lay down my pictures on a table or the floor until I get the pictures how I want them. Then I eyeball it on the wall and use a level to make sure the pictures are straight. This works best if you are not trying to line up your pictures parallel to each other. Generally, I don’t worry about any type of symmetry. You can even group two or three pictures on the wall first, then add each additional picture one at a time.
I like using different types of frames, as long as they complement each other. It’s cheaper this way anyway. Do commit one way or another and decide whether to use similar or complementary frames. For instance, one metal frame amongst a group of wooden ones is a no-no. But a metal frame mixed in with a couple of wooden ones and a painted frame can look nice if they all complement each other.
If you already have some frames that match each other, you can use a more symmetrical arrangement. Also, if you are worried about not getting the grouping how you like it the first time, you can arrange your pictures first on top of some butcher paper. Once they are arranged how you want them, draw a border onto the paper around each frame, and mark where the nail should go. Tape the piece of paper directly onto the wall and nail right through the paper. Then, of course, rip the paper off and hang your pictures.