First- start with a tray that's about a 1/2 to a 1/3 the size of your table. Think of this as your "play pen" for your accessories. It keeps them grouped so they don't look like they're floating in space. I chose this basket style tray from Homegoods but I like these trays here, here, and here.
Next, grab some beautiful books or magazines you have around the house. I used my Nate Berkus book as well as a Philadelphia magazine that I keep meaning to read. Make sure the books you choose are pretty large so they take up half of the tray.
And there you have it! Super easy and you probably already have a lot of these things around your house.