Creating Clothes for Avatars in Open Sim

Within the viewing program there is an option called ‘Appearance’ to change your avatars shape and clothes.
Any art program can be used to create textures for clothes.
To create Mesh clothing you need a 3D program such as blender.

Clothing tutorials:

Mesh Clothes

Avastar: An addon in Blender to help make mesh clothing and models

Upon purchase, of Avastar, you have access to these tutorials: