I just use an old notebook I have and start writing starting from the top of the motor working my way down, writing where to get the stuff and what it cost. This is my current parts list for the '70 SP Buick 350 I picked up recently. It's gonna get added too and changed as I go through it buying what I can when I can. As the title says, how do you do it? Notebook? Word Document? Trying to remember all of it and running to the parts store so many times all the workers know what you need by the look on your face?