The problem with most obvious and familiar emotions is that a word like ‘angry’ gives us an instant idea of what angry means, but not a picture. But when you refer to a specific time when a specific character got angry, what does that really mean? What does it look like? All you really convey is a general, clichéd concept of the kind of mood that person was in. You don’t put the reader in the scene, seeing it.
There are two ways to overcome this. First, you don’t describe the character in a static frame of ‘being’. Instead of examining the look on their face, you describe what they do because of the way they feel. So, Mary might tell Bill that she’s pregnant, and Bill might pick up her favourite hairbrush and hurl it out of the window.
However, sometimes you really just want the character sitting there emoting. So, instead of just saying ‘Sally sat there, looking sad’ what you can do is actually describe what Sally’s sad face looks like. Of course, Sally’s sad face may look like a lot of sad faces, and if you start going into the movements of her brow, and the quivering of her lips, you can soon end up with a face full of tics and spasms that seem to suggest someone having a stroke.
There are only a limited amount of moveable parts on a face and trying to come up with new and interesting ways to describe them can read a bit forced and stilted.
What you need to do is use ‘voice’ to make what you see less objective and clinical, and more from the perspective of the person doing the observing. In that way not only are you seeing the same old facial expressions from a singular and unique perspective, but it also enables you to reveal aspects of the person doing the observing. For example:
Jill’s smile slipped at the edges. Mike put his head down and raced to finish the bowl of ice cream. Three spoonfuls in he heard the first sniff and chanced a look up. Jill’s mouth was a thin hard line, any higher and he knew he’d be locked into those unblinking blue eyes. He had ten seconds at most; keep shovelling. The spoon rattled against the empty bowl as the first tears plopped onto the tablecloth. Mike pushed the empty bowl aside and put a slightly chilled hand on top of hers. “Is something wrong?”