I agree. This is the way I've done it for years. You could do it any number of ways you choose I suppose, but I've gotten the best results with top right to bottom left.
I've seen other people do it another way as well. Use a Y cable, plug into top left and bottom right, and then your guitar into it. I haven't tried it myself though because I can't find my Y cable Someone said it sounds "better" this way, but who knows