How to Set a Pretty Background on your App

I'm currently designing an app and all the content is nea开发者_JS百科rly finished. However, I left the "make it pretty" part for last and it looks extremely bland right now. I have been going with the idea that I could design a simple background image for different sections of the app and let the layouts lay on top of it. The background image would contain certain "boxes" or "outlines" around the text laying on top of this. But would the text move off those outlines if a different phone resolution was used? Is this the easiest/best approach? Also I would like to design my own buttons.

Sorry for being so confusing, trying my best to explain my plan. Thanks!

You might want to read about styles and themes: http://developer.android.com/guide/topics/ui/themes.html