I have a short, stocky friend who has his shirts tailored all the time. I don't understand this.
If I need to get off-the-rack shirts tailored, then I am either buying the wrong brand, size or cut.
Get your shirts custom-made instead.
The custom made shirts I've had made took just three measurements:
Chest
Waist
Hips
If you want your best possible fit you need to take several more. I generate a pattern (on brown craft paper) based upon several measurments. I add 4" of girth (2" of width) to all the measure points. Tighter than that and the buttons will pull at my abdomen when seated and eating.
If you never sit or eat you can go much tighter. I see on TV that Ryan Seacrest (the American Idol host) wears a much tighter shirt when he removes his suit jacket. But I think that shirt is just for the show. I don't think you can sit and eat with a shirt with just over 1" of slack.
When I supply the pattern to my tailor he charges me $8.00 per shirt. If he pins up he charges me $12.00 per shirt. It is both cost effective and time savings to make the pattern. Once you have the pattern you just drop off the shirt and the pattern and no fittings are required.
Make sure that your tailor understands that the pattern represents the seam line and not the cut line. But once that is communicated it is an excellent way to handle the shirt fitting/alteration thing.