To the scientists and engineers at the Gillette Research and Development Center in Reading, England, shaving is a whole science. Everything is decrypted and analysed, from razor blades to user behaviour. And some habits many of us have are actually serious mistakes!Shaving before taking a showerOut of habit and convenience, we often shave before hopping in the shower. That allows us to remove hair and foam residue at the same time as we lather and wash our hair. But it's a mistake! The steam and hot water from the shower soften the skin and prepare it for the razor. Proceeding in this order will reduce the likelihood of getting micro-cuts.Not using creamWhether we're short on time or just lazy, sometimes we just skip the whole shaving cream stage. But once again, that's a very bad habit to develop because foam, gel or even soap can prevent friction between the skin and the blades. Again, this helps avoid micro-cuts, as well as ingrown hairs, itching and tightness.Using a razor with one or two bladesAre you a fan of disposable two-blade razors? Don't want to invest in a razor and blades you have to replace every month? You may be doing it wrong, especially if you want a close shave. Because the more blades there are, the shorter the hair is cut. When a blade passes through, your hair is temporarily lifted by a few micrometres.So, the blade cuts the hair where you pass it through, but the part that is raised isn't cut. If several blades follow the first, each one raises the hair a little, and the next one comes to cut the hair that's still sticking out. Once the hair returns to its initial position, it is much shorter when 5 blades went through it than when two blades cut it.Tapping the razor to remove the hairWe all do this! Tapping our razor against the rim of the sink or on the shower wall to remove the hairs stuck between the blades. Big no-no!This gesture permanently damages the blades—which, yes, are made of steel, but are only a few nanometers thick. To remove those hairs, just run water well above the blades, perpendicularly.Not changing your blades regularlyDon't have time to go out and buy new blades or don't see why you should change them if they're still doing their job... again, this is a mistake. You may not be able to see it with the naked eye, but razor blades deteriorate after each use. There is no ideal duration for the blades—because it all depends on the number of shaves, the type of hair, etc..., but they should be changed, on average, once a month.