"Do a common thing in an uncommon way." Booker T. Washington, American writer and educatorIf you interpret this as "build a better mousetrap," it's a happy sentiment and a rule of thumb for adding a pleasurable measure of creativity to your life. However, rather than helping me Keep Calm and Carry On, it describes a really good reason why it's so hard to do just that!
Doing things in an uncommon way is bound to ruffle more than a few feathers and throw up a lot of roadblocks. It's difficult to Keep Calm while fighting endless turbulence. The best you can do is try and block it out, which isn't so much Keep Calm and Carry On as Fuck Them and Carry On. If you're incredibly successful at whatever it is, I suppose of some sort of calm eventually comes with success. But for the rest of us, not so much.
If you truly want to Keep Calm and Carry On, I'd recommend doing a common thing in a common way. Being ordinary is very calming! Or, if you really need a challenge, stay hidden in plain sight: find an uncommon thing that you can do in the commonest possible way.