Louis Philippe as a pear by Honoré Daumier after Charles Philipon, 1831
If one part of the face must be big, make it bigger. Simplify, minimize, or reduce everything else. What you're left with after all this reduction are the essential shapes, the simple forms of the head and the hair. The most important thing about the features is their relative placement.
Caricature is not the art of accentuation. It's the art of reduction—reduction to essentials.