Nevermind fattened lips and smoked-up eyes. This "scientific" article claims that "a large schnoz in relation to the rest of the face is often a sign of an older person," suggesting "using a contour brush to shrink your beak." [LiveScience]
Having done a lot of facial contouring/shading in my college drama school days, I can testify to the effect of judicially-applied nose shading. I still do this sometimes when I go out, to make my nose show a bit more symmetry.
But to do this right, learn from the master: I'd recommend Kevyn Aucoin's "Face Forward"