Well, in this case it works out really well actually, but you've done very little if any blending of the render INTO the background. Try adding layers with blurs and different blending modes on top of renders to make them "fit" the background better.
Also, pet peeve of mine, the FONT. College profs allow Arial, Veranda, and Times New Roman only for a REASON. Well, two reasons actually *cough*, but one of the reasons is that they're clean and easy to read. Almost ALWAYS use a simple font so it's easy to read, I typically only use fancy ones as the first letters in the word or here and there randomly. For a sig like this, I would probably use "The King & Queen" font as the first letters and then use Lucida Calligraphy, which has a cursive/itallic flare to it but is yet read easily enough.
Also, almost ALWAYS use black, white, or transparent text in your images as opposed to colored, and try to use only one color per sig.
Last thing based of this piece, there's no border. Play with beveling and embossing and/or using the rectangle and oval selection tools to give your images a more polished edge.