When you don't understand how to work with sunshine, shooting on a cloudy day can feel easier. It's a common misconception that you can shoot anywhere, in any direction, when the sun isn't out.
I can see bad lighting when it's a sunny day. Unfortunately, bad lighting on a cloudy day isn't very obvious to me while I'm shooting. It's only afterward, when I'm trying to edit, that I come across unflattering problems such as:
Blown out foreheads
Dark eye sockets
Dreary and muddy coloring
Lack of Pop
There's a simple solution: Have your clients face where the sun WOULD be.
I don't exactly know the physics of why this works, but it 100% does. Even though you can't see the sun to know where it would be, remember that the sun rises in the east and sets in the west. Think about what time of day you're shooting at and adjust accordingly.
Remember, good photos are not made by editing. Good photos are made by choosing food lighting while you're shooting. Hope this helps <3