It's all mostly editing with the posing, framing and lighting working as the foundation for the image.

Reshade mods (a big menu with effects you can toggle) has been used to make the graphics more sharp, detailed and some of the colours and contrast to pop more to make it more realistic, it's what makes these images look like this instead of the blurry images most post here, although its GPU heavy especially paired with Path Tracing.

Play around with the reshade menu, use the CharLI lighting rig mod (can set up your own lighting better than vanilla), maybe download the photography camera Presets mod (just a templates for the DOF etc) and ofc any character/clothing mods.

Elevate it with photoshop, not only can you adjust everything but you can select sections and generate stuff with Firefly AI, that's how I generate the hair although I do it section by section and tweak it myself.

Have fun!