While there are many cases where writers can use movements of body parts to express actions or emotions, be careful of situations where you go from useful use to overly specific, thus strange use. First example:
My face frowned as I thought about his offer.
The writer wants to emphasize frowning, which is fine in of itself, but by specifying that the face frowned, it gives the suggestion that the face has a will of its own, and independently of the person that face belongs to, it decided to frown. Instead, you should specify the person as a whole. In this case, it’s not just my face, it’s all of me, thus:
I frowned as I thought about his offer.
Here’s a second, similar example of problematic use:
My eyes looked at her in astonishment.
Again, by specifying one body part as having the reaction, you’re suggesting that the rest of the person didn’t have that same reaction. Yes, the eyes and mouth are the vehicles for experiencing the emotion the person is feeling, but they aren’t the causes of the reaction.
Looking at things from the other side:
My left hand ached from the impact.
In this case, specifying the left hand makes sense, because that’s the specific part that was injured. If instead we said:
I ached from the impact.
It would suggest that the person’s entire body ached, which is a different story.
Some final examples of what to avoid:
His ears listened to the conversation.
Her nose didn’t like the room’s smell.
James’ brain considered the escape route, and decided it might work.
In all these cases, specifying the organ used to process the information means that organ is in charge, rather than the person as a whole. Instead, we want to write the following:
He listened to the conversation.
She didn’t like the room’s smell.
James considered the escape route, and decided it might work.