Organizing your psd files are even more important that having a clean background space.For starters you should name your layers. Simply rightclick on your layer in the layers pallette and choose layer properties. Then you can change the name. This is very useful (and vital) when working with many layers.Another important thing to do is to organize your layers in folders. This will allow you to affect changes to all of the layers in any one folder at once. For instance, you can move all of the contents of a folder at once, simply by dragging a folder around. You can also hide all of the contents of a folder at once, by clicking the eye.To create a folder, click on the folder button on the layers pallette menu. Then right click (PCs) on the folder to rename it it (Choose LAYER SET PROPERTIES). When your folder is ready, drag and drop the desired layers onto your new folder. The folder should highlight blue and then the layer will appear indented beneath it.You should organize all of your layers, no matter how small, in this manner. This is especially useful for going back and making easy changes later.