Let the reader know whose point of view they’re in.
You should clue the reader in about which character’s point of view the scene will be in as soon as you can. Preferably within the first three sentences.
“Move and you’re dead.” Maggie Somers lifted the .22 higher, trying desperately to keep her hands from shaking.
--From Buried Secrets by Margaret Daley
This was not the smartest way to die.
USAF Pararescue Jumper Manny Péna grunted, tensed his muscles and tried again to flare the canopy on his parachute.
--From A Soldier’s Family by Cheryl Wyatt
Sophie heard God in every explosion of thunder as she listened to the awesome power of the approaching storm. But there was more. There was something coming—something more than rain.
--From Petticoat Ranch by Mary Connealy
In each of the examples, you know exactly who is the viewpoint character right at the start of the chapter.
(You’ll notice that the first two examples show the characters’ full names, which they wouldn’t think to themselves if we’re in their point of view. However, when starting a story, most editors will allow for this kind of “introduction” to the reader of a character’s full name, as long as the rest of the manuscript is deeper in point of view.)