The key to getting a good collar is to frame your head with it. Sounds strange but if you have a long slim face then attaching the bottom with a huge wide collar looks wrong. Same for large circular faced gents. A narrow collar will make it look excessively bigger than it is.
In the two pictures above I have put examples of too narrow and too wide. Both aren't the end of the world but don't you think Adrian Brody looks silly in his super fat and wide collar? And for me the guy above that looks squashed in. Looks trendy but at work that would be an uncomfortable collar. And I've seen people wear those to the office.
Now there is a red carpet man whose collar frames his face and head in much better proportion. Shame he can't do a tie properly but you can't have everything in life.
There are many styles for you to choose and high street shops tend to follow the fashion set by designers. This can work for some guys but for the average working man having a collar that looks natural to his frame is best. If the collar you wear is the first thing you notice when meeting you then it's not doing its job well.
Getting a tailored shirt is the best thing on your back and you'll thank heaven for a shirt that you barely notice during the day. And that's the key, if you are always tucking in your shirt it's either too short or too big in the body. If you're always pulling at the collar to breath then your collar is too tight. There can be many issues with an off the peg shirt and that is one of the reasons to tailor it with an expert.
Look at above collars. Think of what face type you are. Long and thin? Triangular? Round and thick necked? The collar is to balance you out but if you are still unsure then play safe and have a medium spread collar which is the box top left or a slightl longer point length on middle far right box. Experiment with some cheap shirts if needs be if you can't get the help of an expert.
Seeing the right collar on should really make you realise the truth of this but of you are having them made for you remember this may not be an option so trust our clothier and be prepared to adjust hings on next shirts if your not completely sure.
Two great collar styles for this models shape. Top is a wide spread (this is one of my company's shirts so actually not as wide as the name might suggest) and the lower is a medium spread. Both look really great. But to illustrate my point look at the one below those to see a cuttaway collar on the same guy and see what a difference it makes towards the negative.
Also you may want to think how you knot your tie. A four in hand creates a slim off centre knot which is what most of us did at school as it is the easiest. I wear this knot mostly as a like the slight kink in it and the slim knot suits my collar style.
This is my knot which I have just taken a photo of. I could have a wider knot as I wear a reasonably wide collar on this shirt but am choosing a slightly narrower style for future shirts.