Why do my portrait photos look flat and not professional?

[Sequence]

I try taking portraits but they always look flat and kind of lifeless compared to what I see online. I am using natural light mostly. What am I missing to get that more professional look?

[MayanHan]

Lighting is the biggest factor. Even a simple setup like Neewer 18 Inch LED Ring Light Kit adds depth and makes portraits look way better.

[Phil]

Natural light can work but it is inconsistent. I switched to a softbox like Fovitec Softbox Lighting Kit and the difference was obvious immediately.

[Cheeky Shaun]

It is mostly about controlling shadows. Once you add a proper light source your photos stop looking flat.

[Builder]

I thought it was my camera but it turned out to be lighting. Gear made a bigger difference than settings.