So, one wet Sunday afternoon I thought I'd try my hand at pimping (i.e. pimp my ride...) the rear lens caps using simple kids party glitter and self-adhesive bling bought from the local party shop, a circular inkjet print with the number printed onto a black background and nine coats of Estapol varnish.
1: Buy rear lens caps (eBay for approx $1 ea.)
2: Use a small craft grinding stone to remove the embossed [Canon] logo
3: Clean all excess dust and material off the caps
4: I designed the labels using Photoshop - simple numbers with multiple drop shadows in white on a black base. Cut the inkjet print out carefully and stick onto the back cap using glue. Leave to dry 24 hours.
5: Stick self-adhesive jewels onto cap. Position carefully!
6: Apply one coat of Estapol varnish - leave to dry in a well ventilated room for at least 24 hours
7: Apply another coat of varnish and sprinkle glitter into surface while varnish is still wet. Leave 24 hours to dry.
8: Repeat varnish coat up to five or six more times - or till the back cap surface appears smooth. Leave 24 hours between each coat.
9: If, after multiple coats, the surface still feels rough to the touch, lightly sand the roughness off and re-varnish a couple of times to seal the surface.
Once the varnishing is finished, I'd suggest sanding any dried varnish drips off the underside of the cap (i.e. the surface that comes into contact with the lens mounting ring), wipe any dust off with a damp cloth and be very careful to remove any glitter that has not already been sealed in by the six coats of varnish.