Some writers cut every occurrence of “was” or “is” like rotten spots on peaches, as if having them will make readers sick. Be careful with that, because we don’t want to lose the flavor.
Stay focused on the action, showing what is happening, how the surroundings affect your point-of-view character. Then your active voice will naturally displace passive expressions.
When your heroine walks into a room, avoid the descriptions of an interior decorator—unless she is one. Whatever she observes needs to tell us something about her character and her concerns.
Here’s a passive paragraph: No one was in the kitchen. A knife and fork were lying across the plate of half-eaten pancakes. The coffee was still warm, next to the morning paper that almost concealed the gun.
How might we show our heroine’s concerns in a more active sense? To answer that question, we must show why she’s there and what she wants. Susan walked into the kitchen and cleared the plate of half-eaten pancakes from the table. “Jason, I’m home.” When she reached for the morning paper, she stepped back from the gun underneath. Jason didn’t own a gun.
With action, we can keep readers awake, wanting to find out what happens next. We don’t want to put them to sleep.