looking images

se a light tent, that helps with the fairly even lighting, but with just enough to create a shadow and that adds to depth.

If I didn't have a light tent, I would probably use some seamless white paper and lay out the clothing on that. I think it's lying flat, so you may need to use a chair or ladder to go above it.

I can't be sure, but it may be a single light set up, high and to the top left a bit. The shadows on the right are pretty small, so it may also be a bit of fill from the bottom right. Either way, a nice softbox is going to give soft, even, lighting. You may want to experiment with the strength of the light(s) and the distances a bit. It's not like your model will complain, so take a bunch of shots. :)

As for filling out the clothing a bit... I'd probably use bubble wrap or something similar. The wrap with the really big bubbles, which you could probably get from a company such as U-Haul that supports the moving industry, might just do the trick nicely. It's probably what I would try, maybe cut to shape and placed inside. Not a lot of dimension, but it give some, as this image appears to do.