I noticed that when you put a DE blade in the razor (tried various razor models) the blade has a little bit of wiggle room, not much, very minor, and in some cases if you don't spend some time to align the blade before tightening the head, the blade may end up not totally parallel to the guard bar, not by much mind you, or one side can have slightly more blade exposure than the other side. Not sure if this can have an impact on the shave quality. Any tricks on how you make sure the blade is aligned correctly?