I am curious to see different methods of remembering how many times you used a blade. What i do is: - Before each shave, i mark with 1 vertical line, the paper that the blade comes in, using a permanent ink marker. - After the shave, i rinse the rasor and blade under tap water, put them on microfiber cloth to dry and wipe the razor. I just lay the blade flat, i don't wipe it, because this would ruin the edge. Later, it's dry, i put it back on the paper it came with and back into the plastic dispenser that came with Derby (that's the only reason one should buy Derby). - Next time, i mark the paper for second time and so on. What's yours?