Anyone who's ever gotten a critique from me has seen this one sentence on many occasions: What does this look like?
The comment usually follows something like:
1) He looked concerned.
2) He looked nervous.
3) Her face radiated happiness.
Keeping with the whole "show, don't tell" mantra of writing, sentences like the three I've just shared fall into that realm.
Imagine you're with someone, and they are doing something that brings concern or nervousness to mind. What are you seeing that makes you believe they're concerned or nervous?
1) A furrow appeared between his eyebrows. He leaned forward and stared into my eyes.
2) Jerry shifted from one foot to the other, wringing his hands and averting his gaze.
3) Her smile lit her whole face, and laugh crinkles formed at the corner of her eyes.
Does the second set of phrases bring to mind concern, a bad case of nerves, and happiness?
When reading, we're supposed to bond so closely with the characters that we ARE them, so don't tell me "he looked nervous", paint a picture for me of what the POV character is seeing, and let me draw my own conclusion that "he looked nervous."