Diffuser, lots of options, three sheets of tracing paper might work. Whatever you use, make it out of focus. Set up for flash, there are lots of options. I took an old furniture cabinet, cut a hole in the top and shine the flash up from underneath, see photo. Another guy has a glass dining table, flash up from underneath. White plastic cooler material (called “Styrofoam” here" is a great diffuser; you can cut a hole in a cooler, shine the light into the cooler, cut another hole and place film holder over 2nd hole. Or cut up the material, use it to line a diffusion box.
