My collection started out unknowingly. I started buying things for my house about a year before we got married. I would stick it in a large tote and would forget what we bought. We built our house by ourselves (or I guess I should say Matt and my dad did, LOL) which took about 4 years longer than we expected. I didn't decorate at the house we rented because I thought we'd be in our new house in no time. When we finally moved into our new house and unpacked the three huge totes of stuff I had accumulated, I had all of these crosses. I immediately knew that this was what I wanted to do with them.
If you want a feature wall, I first suggest to find a collection of things that you love. For me it was crosses, but I could totally see this wall done in antiques or keys, or whatever you collect.
Next figure out how you want to arrange them. We laid them all out on the floor in front of the wall to try to judge spacing. When we (or I should say Matt) hung them, we just started from the center and hung the big one and worked our way out to the edges. I wasn't going for perfect, so this worked for me. We used small nails for the smaller crosses, but we used drywall anchors & screws for the larger ones. I definitely don't want any crosses falling on my babies!
You could also sketch it on out big paper and use the method that my friend Sarah from Simply Sarah Style did with plates. And be sure to note her lesson of the day!!
Here are some other feature walls for inspiration.
With picture frames - from Design*Sponge
Using Mirrors - from Pottery Barnwith Plates - from Nesting Place