Whatever the make-up objective, the techniques for lightening/shadowing are the basis of the effects you want to achieve. Shaded/dark segments cause that area to recede optically, whereas highlighted/lighter segments make something stand out optically. If you extend sharp lines, for example by extending the naso-labial fold line downwards, this will give a negative and even rather mean effect. The longer the line, the more severe the character will appear. The more quickly you draw the line the straighter it will be, and the more pressure you apply on the brush, the thicker the line becomes.