I used to do this all the time. I believed I could, that I had the power to do so, and I just told them I was binding them and casting them out. It was almost a chant, a kind of mantra. I invoked the name of Christ to do this, again because I believed I had the authority to do so. Basically: "In the name of Christ I bind you, and cast you out. Begone." Simple as that. 

(EDIT: Re-reading this has made me wonder if you mean something different than I do when I say "bind". I do not mean "bind into service". I have never, ever had the desire to do such a thing. Demons are nasty creatures, and I certainly never wanted one as a slave. Not a happy thought. When I said bind, I meant something more along the lines of stopping them in their tracks, like a fly caught in a spider web, and then I'd cast them out of the place where I was, with no permission or ability to return.)

Mind you, it took a long time to realise I could do that, and longer to believe it would work, but once I did understand and believe, I did it, and it worked.

Now, of course, my reality has changed so substantially that such beings have no power over me at all, and there's no need to bind them or cast them out, because they pretty much no longer exist in my reality at all. But when they did...