A question that often comes up during appointments is which side am I supposed to wear my hat on?
Well, tradition states that "a lady should wear her hat on the right". I don't mind traditions. Many are outdated customs that a lot of people don't find too innocuous, while some are mortally offended by them. You can pick and choose I guess. If my dear old Dad had been alive when I got married, he would have walked me down the aisle to "give me away". Of course he wouldn't actually have given me away...it was just a nice old fashioned thing to do. But I do understand that some people don't like the idea because of what it stands for.
They probably gave the same eye roll and tut that I gave when I discovered that the reason behind the tradition of a woman wearing her hat on her right, is that when out, she should always be accompanied by a gentleman who stands on her left. This way, her hat won't interfere with the gentleman to her left, or his view of her face....god forbid he might have to move to her right for a chat.
So, again, it's based on an very outdated custom that really doesn't matter anymore. If a customer wishes to wear their hat on the right to respect tradition, that's absolutely fine by me, just as I would have loved to have had my Dad walk me down the aisle.
However, my personal opinion is - wear it on whatever side you want to. Maybe you have a preferred side of your face, maybe something sitting on one particular side of your face annoys you, maybe your hair is parted so that wearing a hat on the right will ruin your style on your big day. These days a hat is an accessory component of your outfit - a choice, not a requirement - so you want to look your best.
You will find that many hats are designed and made to be worn on a specific side - due to the position of adornments or assymetric brims, usually as a result of this very tradition. However, if you are having a hat made by a milliner, you can specify on which side you want to wear it.