Firstly, verbs indicate action. Actions by your character, actions to your character. Yes people, I'm talking about active vs. passive sentences. Far be it from me to say that passive tense must NEVER be included anywhere in a story. (I guess I should have mentioned with every post that nothing is written in stone... oops.) But. Too much passive tense will have the reader wondering why they're rooting for a hero that lets the universe randomly do stuff to him when the baddie is out there doing things. If you read through your work and notice too many: "Something WAS done BY someone/something else." sentences, you might want to work on getting more active tense in. Remember: put the emphasis on the most important thing. More often than not, that will be your characters. So put them first in the sentence.
No. I am not saying "'was' is evil and should die a slow death". In fact, ask my CPs. I adore "was" in all its forms. But verbs also describe actions. And sadly, "was" is... somewhat generic. As are verbs like: look, walk, have, say and so on. Yes, these verbs tell us what someone is doing, but are they telling us how? No. And that's why adverbs sneak into writing, because suddenly they're necessary to describe how the character is doing something. Do you say something angrily? No. You grind it out between your teeth. Do you walk insolently? No... you saunter. So make sure as many verbs as possible carry enough weight to describe as well. Get it? Got it? Good. Next. (Notice: I'm not saying adverbs are evil.)
In addition, verbs agree with their subjects. So no "He say's" or "They does's" unless it's in dialogue or you're going for a specific flavor in your narrative.
Verbs also lend meaning to a sentence. So sometimes, the way you use a verb can change what a sentence means. For example: "I remembered to do my homework." and "I remembered doing my homework." Yes, they might look like they mean the same thing, but depending on context, the first implies that the homework isn't done, while the second implies that it was done (possibly at some point in the more distant past). This can depend on context and feel a lot, so keep an eye out.
Finally, verbs can indicate things happening at the same time. "Doing one thing, he did another." Nothing wrong with that, but I find that sentence structure addictive. It's a lazy way to show things happening at the same time. As supposed to being more inventive. So... those sentences can riddle a writer's works like weeds. Another one (and I've heard that it can be a red flag for agents) is when a writer indicates two things occurring at the same time, when they're physically impossible. "Standing with his cup of coffee, he sat down." or "Driving home, he got out of the car." Those ones, you have to look out for, because they're incredibly annoying to read.
Look Out for These:
1) Generic verbs and repetition that lessens the depth of your words.
2) Passive tense and gerunds changing the meaning of a sentence or story.
3) Tenses and concurrent happenings that don't make sense.
What is your vice when it comes to verbs?