Cloth works best with single-sided flat meshes (subdivided planes). It can also be used on thin subdivided boxes. Avoid using copied planes with inverted face normals (that makes two sheets of cloth that constantly collide with each other).

For best results, you should use some kind of double-sided shader on the single-sided flat mesh. You may use a simple shader provided with the example project; you can find it in the Textures materials and shadersShaders directory. It doesn't support shadows. You can also find good double-sided shaders in the Asset Store; I can recommend the Double Sided Standard Mobile Legacy Shaders package created by Mario Lelas.

Cloth components can be used with any Skinned Mesh Renderer. So you can make parts of your characters be simulated as cloth. The best practice would be to have a second Skinned Mesh Renderer with just the cloth mesh (it will be far easier to constrain such mesh than trying to constrain the whole character).