https://sims4studio.com/thread/4324/tutorial-detailed-guide-create-clothing?page=1

A Very detailed Tutorial about: by: EvilTiptipINDEX:

1.INTRO

1.1 Things you will learn in this tutorial.

1.2 Things you need to know before starting this tutorial.

1.3 the following software should be installed on your pc.

2.Meshing

3.UVs MAPPING

3.1 UVs basics

3.2 UVs Position For EA Map

3.3 Adding Texture On UVs Shapes

3.4 Fix Texture Position Using UVs Layout

4. Textures

5.BUMP MAP

5.1 What is Bump Mapping?

5.2 creating Bump Map for our item

6.Reflections And Shadows

6.1 Specular Maps.

6.2 shadows