So much comes down to personal taste on the brand of pattern that you use. I've found that US patterns, McCalls, Butterick, etc. have a lot of ease and are very broad across the shoulder. European brands such as Burda are closer fitting with a slimmer look to them.
It's fun to have a look at expensive designer stuff, too, as it's easy to copy any features that you particularly like. If you're going to go to all the bother of making a shirt, it may as well look like an expensive one rather than one from Asda. My OH likes the style (not necessarily the fabric) of Angelo Galasso shirts, having seen Eddie Jordan wearing them on the F1 programmes, so I just transferred a few of the features of those onto his shirts. He also really likes Liberty lawn for his shirts as it's such a comfortable fabric to wear.