>>153726I'm not into feet myself, but being into giantess porn I do come across it mentioned a lot. However, I skim over a lot of it, so I can't get exact pointers.
In general, it's probably a lot like writing any other part of the female body: mention the curves, softness, stuff like that. In the context of giants, you can get more in depth with things like texture and ridges of the skin, depending on the size of the person in relation to the foot. I know a lot of foot stuff also involve odors and sweat. Can't help you out there, that's outside my wheelhouse for sure.