For Slouchback Saturday today, let's continue the discussion of the process of figuring out how to draw someone for the first time.
There are a lot of sources out there to take you step by step through starting with an oval or a rectangle or a figure 8, dividing the space up, adding ears and hair and voilà! You can caricature passers-by at the fair! So I won't go in that direction.
Instead, here is an example from one of the masters in capturing a difficult face: Pat Oliphant's caricatures of Gerald Ford.
These are actually tracings I did as a kid in ballpoint pen and ink (even the imitation ben-day in a number of them -- well, for those I used a ruler rather than tracing the actual ben-day lines). I drew pages of Oliphant's LBJ, Nixon, Ford, Carter and Reagan; I started with Nixon because of the drastic differences that evolved in Oliphant's caricatures of the 37th President. And of Oliphant's signature over Nixon's career.
When Nixon tapped Ford for the Vice Presidency after the resignation of Spiro Agnew, editorial cartoonists braced themselves for a challenge. Nixon and Agnew had faces that easily lent themselves to caricature (as did LBJ and Hubert Humphrey); many cartoonists were drawing Nixons that were barely humanoid yet instantly recognizable. Ford's face was by contrast, plain and unremarkable.
You can see that Oliphant quickly settled on the chin as the feature of Ford's face to emphasize. After about a year, he exaggerates the entire lower half of the face. Contrast the large one on the top row, drawn as Ford took office as President, with the third one on the middle row. In both, Ford's mien is thoughtful, but the effect is quite different. One trait that is nearly always present in Oliphant's drawings, moreso than in those of any other cartoonist, is that Ford's eyes are shut.
If you're interested in comparing other cartoonists' approaches to Gerald Ford (plus one of Oliphant's not included above), Vancouver cartoonist J.J.McCullough has posted 14 examples here. Which he probably didn't trace with ballpoint pen. See also Oliphant's Presidents: 25 Years of Caricature.