As someone who has created scenes for over 15 years I have a bit of experience with this subject.
Early on, I didn't have backgrounds or groundwork so I tried extracting foregrounds from pictures and pasting them onto pictures I found online. For me, it was way too much work to try to get lighting correct and clean up all the artifacts. I eventually stopped using the digital backgrounds and switched to large pictures (72" x 24"). I hung these on the wall behind my scene. These were much easier to work with. You still have to light the scene correctly to ensure it matches the background, but this is part of the composition process anyway. Cleanup is much easier now, as it involves removing any reflections from the picture.
Once I had some decent sized ground work, things became even easier. Essentially place the figures/models/accessories in the various places and shoot. Scene cleanup consists of digitally painting out any figure bases, removing any background reflections, and digitally extending any part of the scene missing background or groundwork. For instance, if you shoot a low angle obliquely across your groundwork, you will often be missing a portion in the front or corner of the picture. This can be digitally filled in (particularly these days with AI). The other option is a tighter crop,, but this can result in an unbalanced picture. This is the reason, all my groundwork is setup on an angle, to reduce having to shoot obliquely across it.
Occasionally I will layer in some fog, essentially consecutive layers of translucent grey (10% opaqueness) with increasing foreground excluded.
Aside from that, I reduce color saturation and tweak brightness and contrast. Lastly I apply some sharpening, which helps with shallow depth of fields.
In the following pic, I used AI to assist filling in the leaves in the bottom right corner of the picture (in front of the plants) as that was the edge of the groundwork. It took many tries and I still had to manually adjust the result I kept. This allowed me to maintain the image composition.
