Ok this tut is a simple one. It will introduce you to the use of blend modes and filters.... so open up photoshop and get going
1. Open a new canvas (ctrl+N). For this tut I am going to use width-400(px) and height-400(px) with resolution 72(pixels/inch). Make sure u set the mode to RGB Color. I am setting the contents to 'white'.
2. Make a new layer (shift+ctrl+N). Get the Paint Bucket Tool(G). Sometimes the gradient tool comes up so cimply right click it and select the paintbucket tool.