Are there any particular techniques or methods that you've learned over the years that you find invaluable when working on auto upholstery?

One of the most important techniques that I've learned is to take my time and do a thorough job. It's easy to rush through a project and make mistakes, but taking the time to do it right the first time will save you time and money in the long run.

Another technique that I've found to be helpful is to use templates. When you're working on a complex project with multiple pieces, it can be helpful to create a template out of cardboard or another sturdy material. This way, you can ensure that all of your pieces are the same size and shape, which will make the final product look much more professional.