I'm a total newbee to mobile app development and am having trouble with the graphic design part although endlessly trying to find tutorials about it. I am using GIMP to create graphics such as buttons and background but don't have a proper understanding of the process. Do I create a background and then layer it with the buttons and then save each layer separately? Do buttons have to be squares or circles or can they be stars for example? Do I need to create every background and button as a 9patch or do I just create 2-3 different resolutions? and finally where do I set things like dp?