Even good writers sometimes lose focus. Often it's only a line or two of slack summary or position blocking, but if it comes across as that-- as filling in-- it breaks the narrative drive and the "reality" of the fictional dream you're creating.
Vagueness is always the enemy of verisimilitude.
These vague passages are often right at the beginning of a paragraph, sometimes the beginning of a scene. Often it's just one sentence that performs one job -- making a transition, or moving to a new setting-- but not the job of keeping the reader in the experience.
Here's an example:
Phillippa arrived at the airport.
That gets us to the new situation, but what's missing? Yes, often the rest of the paragraph supplies the point of view, the setting, the emotion. But even one line of just utilitarian narration can lose the reader's attention and that all-important belief. We can't afford to waste space, any space at all, but especially that essential real estate at the beginning of a paragraph. In fact, transitions are exactly where you don't want to slack off, because the reader really needs to experience the change of scene, POV, or situation as something vital and IN the story.
So how to infuse some vitality into those dull lines? A lot will depend on the viewpoint approach. If you're in a close POV, go to the character, and narrate it from her perspective. If you're in Phillippa's POV above, make it about her experience, not some generic arrival.
When Phillippa arrived at the airport, she looked around anxiously for her mother. But she wasn't at baggage claim, and Phillippa finally tracked her down-- typical-- at the bar.
Notice that making the movement (arrival) in a dependent clause leaves the all-important independent clause for something in the character-- a thought, a perception, an emotion.
So what if you're in a more omniscient or distant POV? Well, the great advantage of a more distant POV is the flexibility it gives in description. No need to filter the description through a character-- you can use your own observations and voice to fill in the world of the story.
The flight from Memphis came in so early, the airport was almost deserted, most of the stores shuttered and dark. But the bar was open already, or still, and it was there Phillippa found her mother.
Point is... you can't afford even a line that breaks the continuity of the narrative you're creating, the world you're building for the reader. When you revise, watch for those wasted-space lines and see how you can make that part of your narrative-- incorporating your voice, your setting, the character-- something that makes this more than just a space-filler. Challenge yourself. You can do it. :)