I like that bit with the string and the workmate.

As far as this goes:

To check the blades for out of true, install your wheel and see how it splits the space between the tops of the blades. If off, chances are the blades are bent...

I would add that you should flip the wheel and check it both ways. I thought my fork was slightly off for years and then one day discovered the front wheel was dished. My bad.