Open a new blank document and choose 512px for both width and height. This is the maximum size required for icons (Mac OS X Leopard). Create an ellipse above the center and to the left and name it "outer rim" (1a). Make two copies and scale them down (1b). Name the first "inside." Move the other copy down, naming it "bottom" (1c
Create a new copy of the smaller ellipse and make it yellow, which will make the paint's surface (2a). Position it inside the bucket, erasing the unnecessary pixels (2b). Name this layer "paint." Now make a rectangular selection with the Marquee Tool (M) on the "bottom" layer and fill it to complete the bucket (2c). With the "bottom" layer selected hit Command + T to invoke the Free Transform Tool. Right-click and choose Perspective. Now drag the bottom corners towards the center to apply the correct perspective deformation (2d).