The main steps to create a custom armour or outfit for Fallout 3 are: If you want to adapt existing armours or outfits to other bodies you will have to follow the steps explained here, except that you won't have to create the mesh (but you may probably have to adapt it to the new body), the textures or the UV maps. If you only want to change the textures of an existing piece of clothing or change its properties and bonus, just skip the first part of the tutorial. This tutorial shows all the main steps you need to follow to create an armour or an outfit from scratch for Fallout 3.
3.2.3.1 For objects or parts of the armour with simple shapes.3.1 Importing into Blender all parts of the body.