I align using a 6-foot folding ruler, some masking tape, pencil and either a spirit level or rafter square (if your garage floor is pretty flat & true).
Roll the car to a stop (don't lower it from jacks) with front tires at corect pressure.
Mark the spot at 3:00 on the fat part of D/S front tire using the tape and pencil. Use the square or level to mark on the floor (tape and pencil) the corresponding point directly below that spot. Do the same for the 9:00 position on the P/S front tire. Mark these with an "R".
Roll the car backwards 1/2 turn of the tires -- your marks are now at 9:00 on D/S and 3:00 P/S. Same thing with level or square. Mark these with an "F".
Roll the car back some more. The distance between the marks from the front of the tire minus the marks from the rear give you a toe-in/toe-out figure. Note: the marks are sort of reversed on your floor, i.e. the rear marks are the ones farther forward.
You have to interpolate a bit as the measurement you are making is at a diameter that is less that the full diameter of the tire -- unless your aim is zero toe-in in which case zero is zero.
You will have to experiment a bit to learn how much you turn a tie-rod to get a particular change in toe-in.
This is just one method, there are several others using scribes, chalk, thumb tacks & string as well as assorted tools for doing this. Find a method that works for you, keep notes and soon it will be a ten-minute job to set the alignment.