Some of the fellows at the dragstrip will paint a stripe of white shoe polish (like you wipe on your tennie-pumpers to whiten 'em) maybe 3-4" wide all the way across the tread on a tire to determine the best tire pressure when using street tires.

As far as doing this to check front end alignment, I think you'd see toe-in / toe-out and tire pressure, but I doubt you'd see camber and caster is out of the question.

If you don't feel confident about learning to do it yourself, do like you said, get it close and drive it to a shop.