Creating Costumes from Scratch.

Hey eveyone, well I was wondering, how would you make like cs outfits from scratch? I looked back through the 'Fiesta Help' to page 42 and there was one thread like this but with no replies so I was wondering if anyone had any ideas that they could post here ^_^ Ik my way with Nifksope like .nif editing and I have texture edited before but now I'm wondering how to make outfits from scratch and how to texture them and everything ^^ If there is already any guides to this please do link so I can follow it ^^
Regards~

Open an existing costume and figure it out from there ;)
Should make sense once you open one.

I have before, you know I mean like making the outfits model, I have worked on re texturing outfits before to make new outfits but I never made completley from scratch.