If your blades are true (decent carbons or glass) and you set it up with a pitch gauge to have the same pitch on both blades, you probably wont have to mess with it.

Not always true and more and more people don't even know what a pitch gage is....

One of the things I do to track them when I have to is use erasable marker to slather one blade tip red. It doesnt change balance like tracking tape and it wipes off when you're done.

Great idea!