Remember the old Hefty commercials?
Don't let your verbs be wimpy, wimpy, wimpy
Do you need more muscle in your writing? Weak - wimpy, wimpy, wimpy - verbs can't sustain your ideas.
A good editing technique is to read through your writing and underline each verb, including helping verbs. The strongest verbs are those that offer the most information; the weakest verbs offer the least. A new verb or a shift in tense might be the edit you need to tighten your writing. Often, any form of the verb to be can be strengthened.
For example, if I write, "She is in the store," there's very little the reader learns about this woman in the store, except her location. This is an example of the verb to be doing very little. What can a stronger verb offer? What happens if you swap out "is" with "romps" or "searches" or "hides" or ... something else? Suddenly the character is animated and the reader has learned more in short sentence. And that's your goal as a writer: to offer as much information in concise sentences. That's not to say that you can't vary the rhythm of your writing and use longer sentences. Prose should borrow a lesson from poetry and the writing should be as concise and precise as possible, even in longer sentences. Each word should offer the reader something new.
Save to be for those times when you declare something about the state of being. If you do, then the verb will stand out.