Creating seams and unwrapping tells Blender how to project the 3D surface of the clothing item in 2D. Before you can apply any texture appearance changes, you need to create a texture map, which is the specific 2D image you apply and save your textures to.
To create a new texture map:
With the clothing mesh selected, navigate to Properties Panel > Material Preview tab.
Select the + New button.
Next to Base Color, select the yellow dot and click Image Texture.
Click the + New button.
- Name the texture image the same as your clothing mesh with a _TXT affix.
- Set the color to black, or any base color of your preference.
- Keep the rest of the default settings.
- Press OK when completed.