Face a window or turn slightly toward it. Soft daylight across both cheeks is easier to work with than direct sun or a ceiling light that darkens the eyes.
Turn off strongly colored lamps nearby. Mixed orange and blue light can make the two sides of the face look like different skin tones.
A situation you may recognize
A sunny window creates a bright patch on one cheek and a dark eye socket.
Step out of direct sunlight or soften it with a curtain, then compare both eyes. Do not compensate by over-brightening the whole file: that may erase the already bright cheek while leaving the original lighting imbalance.
Find a window without strong direct sun and turn off a colored room light for the comparison.
02
Make the first version
Face slightly toward the window and make a second frame with a small turn. Compare the darker eye and the bright side of the forehead. Choose the source where both remain readable; the aim is useful facial information, not eliminating every natural shadow.
03
Choose the next move
If the face is readable and only the room is busy, edit the background. If highlights are blank or one eye disappears, change the shooting position first.
Try this before committing
Stand beside a window rather than directly in front of strong sunlight. Look for detail on both cheeks. If one side is nearly black, turn toward the window before taking another source; asking generation to recover it adds uncertainty.
Face toward the soft light with a slight turn, then compare both sides of the face. Direct sun can create hard patches, while a bright window behind you can darken the face. Move position before trying to fix the exposure afterward.
Do I need an expensive light?
Not for a useful first source. Stable soft light and a clear eye area matter more than equipment labels. Check several window positions and times before buying gear; a badly placed extra light can add a second color or harsh lens reflection.