could be a japanese maple. there are some varieties that look a whole lot like weed plant foliage.
you usually either wrap the tree where you're going to wrap the wire with a small piece of light cloth or something to keep it from cutting in, then you tension and bend the tree and attach the wire to a fixed point. you can use nails on a board outside the pot, or a small board or stick and put it up against the tree (you could once again wrap the tree or your stick to prevent damage to its bark) and wrap around it to make your tension. LOTS of different ways to do shit...getting creative is the fun part.
and go back and look at page 1. one of my posts on down the page has a wired tree, to give you a basic idea..