To accessorize with plates, you have several options. You can see in my first picture that I have a plate holder that holds multiple plates. I have had this for awhile - my parents gave it to me as a gift and my dad painted it white (it was originally black). I have also seen these same kinds of holders that hang vertically as well, holding any number of plates. You could find something like this online for sure - I think this particular one came from a store in my parents' hometown. If you're not looking for it, you're sure to stumble upon one!
Another option is to get a plate hanger from a home improvement store - in fact, I have also gotten them from Target in the hooks/light switch covers section. These hangers come in different sizes and all you have to do is measure your plate and find a size that will fit. The hangers usually fit a range (like it will say 4"-7") and there are springs on the back that keep the hanger snug on your plate so it won't fall out of the brackets. The package also contains the hook and nail you will need, so it's super-easy. This plate is hanging between my countertop and cabinets - I think it's an unexpected and often forgotten place to display something if you don't have a backsplash.
I also have a plate displayed in one corner of my kitchen on a plate stand. It's a great way to show off a plate that is odd in shape or has a large rim that wouldn't fit into the aforementioned plate hanger. Plate stands like these can be found at discount stores like TJ Maxx or Marshalls, in the home section of Target or Wal Mart and I've even seen some plain ones in craft stores. They usually come in different colors/finishes and have a ton of embellishment or none at all.