Photoshop design of user interface objects and layers

I have a Photoshop file with layers that need to be filled in with buttons and backgrounds that will be used for a software application user interface. I supply images that show what the buttons and backgrounds should look like. But these images are low resolution and I need them to be re-designed at a higher resolution and with more lighting effects for a more photo realistic effect. The provided Photoship file has a layer group called "Channel Strip Layers To Design." These layers need to be filled in with artwork. A layer called "Basic Idea Of Finished Look" shows approximately how it should look after those layers have been designed. Another layer group called "Basic Idea Of Elements" shows approximate look of button and background images that need to be created.