Loosen the nuts and remove the old glass light shades and bulbs so you can get to the body of the fan easier. Next, remove screws and each blade arm from the fan body using a screwdriver or drill (Image 1). Flip each blade over and remove the screws that hold the arm in place (Image 2). Wipe down each blade with a damp paper towel to remove dust.
Wrap the tip of each blade in painter's tape, then drop down a few inches and wrap the blade again so you end up with a white stripe near the middle of the blade. Make a note of the location and thickness of the tape strips so you can replicate your design on the other blades (Images 1 and 2). Spray paint each blade using a light, sweeping motion (Image 3). After a few minutes, gently remove the painter's tape from each blade.
Pick up a few sets of decorative tape that are packaged together, or pick your own patterns and colors. Place the first piece of tape across the blade, aligning the edges of the tape where the painter's tape previously was. This will help hide any imperfections if the paint line isn't super crisp. Add more strips of painter's tape, but don't get too heavy handed as too much additional weight on the blades can throw the fan out of balance. Cut slits in the tape when you reach the curved end of the blade, and tuck under (Image 2).
Re-install each blade arm onto each blade, then secure the blade arm to the fan body using a screwdriver or drill (Image 1). If using a drill, go slow and be careful to not strip any of the screws. Replace the shades or install new ones with a screwdriver (Image 2).