1) Open Photoshop and go to File – New to create a new document. I set mine to be 200px x 200px and 72dpi with a white background.
2) Select the Ellipse tool (fig 1) to draw a circle shape (fig 2)
3) Right click on the shape layer and select Rasterize Layer
4) Now the layer is rasterized, select the polygon lasso from the toolbox (fig 3) and cut off a corner. ctrl-x to cut it then ctrl+v to paste it back in (fig 4)
5) Using Image – Adjustments – Hue/Saturation to adjust the colour of this newly pasted layer. With this layer selected go to Edit – Transform Path – Rotate and rotate the layer until the layer is lying opposite to the way than it was originally lying (fig 5)
6) Double click on the same layer and in the Layer style select Gradient Overlay. This is where you can have fun playing with gradients and colours. What you are looking for is the gradient to go from dark from the ‘fold’ to light at the edge by adjusting both the gradient and the angle (fig 6). Now do the same to the original part of the circle to bring it to life.
7) Your finished product shoud look something like the image below. It’s not a bad effect for just a few minutes work! I have also included the psd file for you to download here >