Look at these images. Do I need to put a label on them so you know what the character is feeling? No. Why not? Because these are well-drawn and the emotion is clear. It’s shown.
The same goes with writing. We don’t need to label characters as annoyed, happy, in love, scared, shocked, etc. We need to show it. (Picture books are often the exception to this rule.)
Let’s take Ms. Bunny above. She looks shocked to me. So what happens when a person is shocked (I don’t mean the electrical kind)? Eyes go big or widen. A hand might come up to cover an open mouth. Someone might take a step back or sit down suddenly. A face might pale. The person might gasp. If you describe your character experiencing being shocked, you won’t have to use the “shocked” label.
I love the image of the annoyed penguin. We know what is annoying him and what he plans to do about it. What do you when something is flying around you and it is annoying? First, perhaps wave the insect off. This is almost a subconscious reaction. But after a few times it impinges on our consciousness and we get annoyed. Now we might be slapping at the bug. Making noises of irritation. Then finally get up to get something to kill it.
Mr. Frog is obviously scared. He’s jumped up. His heart is probably pounding (although this is so easy to overuse). He might be sweating. Eyes dilate. Breathing rate could increase. A hand/paw/webbed foot might go to the throat. A body can shake; a hand tremble. If one is like the fainting goats, one might pass out.
So next time you are tempted to write something like “Sam was happy.” Instead think about what that looks and feels like. Observe yourself and others and write was happiness does to a person. Show the reader that instead of telling a “label.”