Q: When do you use a scene break, and what’s the format?

A: I asked a few editors/authors about this. So, you designate a scene break with four asterisk, centered, in between the two scenes:
End of scene one
Start of scene two

Use them any time there is a change of: Time (next day, that night, etc), Place (If a character is at home, and you want to cut to them arriving at work), POV change.