What is the correct procedure for applying textures?

[micheus]

Don't care about old tutorials about UV because that has been not changed too much.
Although, there is a small difference on the AutoUV editor from the old UI (until v1.5.4) and the new one after that.

The process is really the latest one you figured out. You must first unwrap your mesh in the AutoUV Segment window, then in the AutoUV Editor window you make any adjusts, cuts, stitches, ... and then use Create Texture which will result in a new material created and with a white image assigned to it. Sometimes you can get that image with the default alphabetic pattern.

When you choose the Create texture you have some options like dimension and some layers option.usually you are going to chose to draw background, face, edges. All of then have options. You need to check and try which one satisfies your needs.

That white image if it has the edges drawn can be used as reference in a external painting tool. You do that by using the context menu of it Make External.

After the texture creation, you can also replace the image by the one you use to import in case you don't need to export the Base one for painting.