Alignment seems to be one of those things we tend to overlook when doing preventative maintenance. When we have to replace tires because of poor alignment this is when we tend to have a little more focus on the problem. Unless there is a hard pull or a shimmy we cannot figure out or live with we tend to ignore it. When we do a pre-trip inspection one can feel the steer tires to determine if an alignment is in the near future. Looking at a tire will also tell you if there is a problem, cupping, river wear, and any irregular wear can be seen. The problem with waiting till you can see it is, once a tire gets into a wear pattern it probably will not stop wearing in that pattern even if you get repairs or an alignment done.
Reading a tire is something of a knack that comes with doing it regularly. There are many photos of tire wear on many tire manufacturers web sites, so seeing them on someone else's tire is better than seeing it on yours. If you do have odd wear you can look it up and compare with other wear patterns on the web. These photos could tell you if you have a serious issue or just an alignment problem. I wouldn't go into a shop and tell the tech what I think the problem is because I may be wrong. The photos are just going to teach me something about tire wear in general, and allow me to be better informed when I do go to a shop.
As I said earlier feeling the tire wear is better than seeing it. With that said, you can get with any good alignment shop and they can teach you how to feel the tire for any wear if there is any. So this is how I do it. It is done bare handed so the slightest wear can be felt. Sliding your hand across the tread in each direction, inside to outside and outside to inside. If there is an alignment issue you will be able to feel a "sharp" edge one direction or the other at the edges of the tread ribs. If there isn't an issue it will be smooth each direction. I also feel for smoothness around the circumference of the tire. Any waviness and I know I have an issue. It may not be an issue with the steer axle; it could be with either the drive or the pusher axles.
When getting an alignment done a two or three axle alignment, which ever you have, needs to be done to insure the truck travels straight down the road and the axles are not fighting each other. The purpose of an alignment is to make the truck drive better, make the tires last longer and to improve fuel economy. Improving fuel economy is my biggest goal since we started with the Freightliner Cascadia. Tires can help by lowering rolling resistance but these tires are expensive, so we want them to last as long as possible by keeping the truck aligned. On the new truck after it was all put together, it went in for 
an alignment check and all was well at this time.
When everything is new and just assembled, there will be some "settling" of the suspension and frame. An alignment was in store for us as the truck had started pulling to the right after we had several thousand miles on the odometer. While in Kansas City a few weeks ago we called on our friend and alignment guru, Chad. Chad who is the owner of Alignment Solutions uses the M. D. Alignment ProTrack system for alignments, and I believe he has done a very good job of straightening out our truck. Chads business motto is "No Excuses just Solutions" and he believe 100% that he will everything in his power to adjust a truck to go down the road straight, after 21 years of doing alignments he is pretty darn good at his job. Chad also understands straight trucks with lift able axles and knows they can be trick to get right. The factory did a great job on the steer axle but the drive and the pusher that were square with each other, were pointing to the right, hence the pull to the right.
Working with Chad is always easy as he understands trucking and that we do not always have time during the normal 9 to 5 day to stop and have an alignment. We called Chad on a national holiday weekend and he was able to meet us at a mutually convenient location with enough room to move the truck forward and backward to perform the alignment. He does have a shop that he works out of when a driver can get an alignment during normal shop hours.
While Chad was aligning the truck he explained the whole process to me and allowed me to watch, I did try to stay out of his way, while he did his magic. A few adjustments and shim relocations and we were on our way, Thanks Chad.