Most sentences of any length involve a subject and an object. The subject does the acting; the object is acted upon.
A clear example would be: The hawk swooped down on the snake. The hawk is clearly doing the acting here. The snake has no say at all.
The worst thing you could do here is to say: The snake was swooped down upon by the hawk. Here you’ve switched positions. You’ve put the snake in the place of the hawk, when he’s clearly doing nothing, not even getting away.
There’s a more subtle gaffe as well: The hawk was swooping down upon the snake. There are reasons for adding a verb be and giving the -ing form to the verb, but make sure you have one.
For example: Beowulf gritted his teeth as he was ripping the arm from Grendel. Okay, it shows simultaneous action, which is one good reason to use an -ing form of a verb. (AKA the present participle for those who care about such things. An excellent link for those who want further information can be found here.)
There’s a time and place for this form. “I’m thinking,” conveys a different shade of meaning than, “I think.” And “Whistling to himself, he walked down the road,” is a lovely way to portray simultaneous action and show a character being satisfied with himself, rather than telling it. It would be particularly effective if this character had just killed someone.
But Beowulf could have gritted his teeth as he ripped Grendel’s arm off. It’s punchier, (even though it ends in a preposition). You don’t need the -ing verb there.
It’s something you need to keep an eye on as a writer. It’s one of my personal weaknesses, and too many -ing verbs in rapid succession tend to draw attention to themselves. Ration them. Go with the simpler form of the verb if you can. “She ran toward me,” conveys slightly more agency on the part of the character than, “She came running toward me.” And especially if you were going to add the phrase, “screaming in fear,” the first form would be preferable.
It’s one of the many joys of editing, all the things you need to look for. But you’ll end up with a stronger story for it, and that’s really the main thing.
Keep writing! : )