I bought 3 or 4 shirts in my last trip and only one of them fit. The others were too large, but I've found that things don't fit me right off the rack and altering them gives a much better result.
So for this shirt I took in the side seams where it needed it, because it was gathered at the top, it had way too much material, so I just pulled some of the bulk to the sides.
This one I removed the trim on the bottom and shortened it then sewed it back on so that it was more of a balloon style shirt - this was the best result. It took an older style shirt and made it a bit more modern and a better fit.
This last shirt was too big in the stomach, wasn't fitted at all and the sleeves were too long for me, so I shortened the sleeves, and made 3 seams up the middle of the front and stopped at the bust line so that it gave more shape to the shirt and now it looks way better. I've always hated shopping for clothes, they never fit in the right areas, but now I can look for used clothes (that way if I ruin them trying to alter them, I haven't lost too much money!) with alterations in mind. I suggest this to anyone that has similar problems and can do a basic seam on a sewing machine!