I picked up this great guide from Pottery Barn with directions on how to lay out wall frames. I've always wondered what the best way to hang frames along a stairway to they look right. The key is to set large anchor frames which establish an invisible line parallel to the stairs, then balance smaller frames around the anchor frames.
For a collection of frames on a regular wall, set the large anchor frames in a row. Then add four smaller frames (of the same size) in the corners above and below to establish an invisible box. When adding additional frames, align them to the edges of the invisible box.Aaron Brothers is a great place to purchase quality frames. Also, they have a wide selection of various sizes in the same style, and if one store is out of a specific frame, changes are you can find it at another. Aaron Brothers can be on the pricey side, but if you wait until one of their Buy 1, Get 1 for 1 Cent Sales (I believe they're semi-annual), you'll pay about the same price you'd pay for Walmart frames, but you'll have much nicer quality frames.
Before putting up my frames, I measured the final frame sizes, created mock-ups out of scrap paper, and taped the placeholders on the wall to make sure it looked the way I wanted.
