I need help getting a shadow/reflection under the woman’s feet to sell this shot. I have her lowered as far as I can without starting to cut her feet off into the floor. Right now looks like she’s floating. Thanks.
Go into Edit -> Preferences and under the Add-ons tab, search for Import Images as Planes, and activate the add-on.
Then, go to File -> Import -> Images as Planes
Here you can select your green screen footage. You can use movie files or image sequences as well. By default, Blender will create this material, which is good, since we need a shader in order for our figure to cast shadows (if you plug your image directly into the material surface output, you won't get shadows).
However, if you don't want any extra shading on your figure, you can switch out the Principled shader to this setup:
With a simple sun lamp, I got this result:
Be sure that your floor also has a proper shader like a Principled shader or Diffuse shader, otherwise you also won't get shadows.