I usually start out by checking to see if the steering wheel is centered, when the vehicle is driving straight ahead. Then I measure, rim to rim front center (center of rim outer, top to bottom, as close as you can guesstimate) and compare it too the same measurement front rim to rim rear center.
Another quick check is to park it after driving in a straight line, walking around front, standing back about fifteen feet or so and just looking at one front, compared to the other (are both tires facing the same direction?). And at the same time, compare the front with the rear, everything should be pointed forward and parallel. The front tires should be sitting equally inside the fender openings. Pretty common to bend a trac bar and have the whole front end shifted slightly to one side or the other (this will also pull your steering wheel off center).
The tires are going to turn (to lock, left or right) at slightly different angles, it's hard to see excess, from normal (that is why they make alignment machines). This unequal turning of the front tires can be normal and is what causes the steering wheel, to tend to, center itself (somewhat) after a turn.