Good lighting really helps, but newer smartphone cameras have better sensors that do compensate for that a bit. I used to spend more time taking outfit photos when i first found YLF but now I just go with my highly imperfect mirror selfies.
For me, the editing after taking the pic is key. I correct the perspective distortion (although that creates some leg elongation which is flattering but not necessarily true to life) — basically using the photo editing tools in the iPhone photos app to make the edges of the photo roughly parallel to the edges of the mirror frame. I crop so that a lot of the background is eliminated — I find some participant photos here hard to see because the subject is tiny in the frame. I brighten the shadows a bit if needed and adjust the color tone and saturation to reflect what I see IRL because sometimes the light/color is either too contrasty or too flat.
If you can take photos with diffused, not harsh, front lighting rather than with a bright light source behind you, that helps too. Outdoors is not always better. The best light can be bright and diffused, like midday on a slightly overcast day. You’re basically trying to avoid strong shadows.
Of course there are ways of posing and angling the body for the most flattering effect, but I’m not an expert on that and don’t feel the need to do much for an outfit photo — I feel silly posing for photos!
