first i put down a circle shape with a color that i felt seemed fit. then i put a bevel and emboss FX layer on the circle to give it a shadow and good definition. next i put down a bunch of rounded rectangles on the edge of the circle and made them gray. then i put the numbers down. next the arrows. then finally i implemented a timeline and made the arrows show at a certain time to make the clock look like its working.
Gage's blog 