First, I used PhotoShop to try different arrangements of frames. If you do a search on Google, you'll find tons of gallery wall examples. However, none of these are any help if you already have your frames because your frames are not all the same as their frames. So, you're kind of on your own. I made several different arrangements, printed them out and Kevin and I narrowed it down to three.
Then I arranged the paper bags on the wall. This was a bit of a pain, too, because I wanted it to be centered on the room, so there was more measuring involved, and about three different sessions of moving them over just an inch, and then moving them again, etc. I finally got them all up and as close to centered as they were ever going to be.
Then came the easy part. You pound the nails in where the holes are, take the paper off and hang up the frames. Really. It actually works. Every frame but one was exactly where it should have been. You can see the one on the bottom right is too low because I measured wrong.
So there you have it! It was a lot of work, but it was worth it in the end. If you try the other method I linked to up top, I'd like to know how it works out, it seems much easier!