I am male. I have asked counter girls and friends, but are there rules of thumb to follow? There are several styles of hat, and it is for a casual but important function which is essentially a job interview. I normally do not wear hats so am out of my league. I have a square face and of average hight, heavy build. If there is a fashion site or buying guide for hats on line, that could give hintson materials and brim sizes and crown hights, it would be very helpfull.
Thank you.
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You must be the one that feel comfortable with a Stetson ,if it looks good on you .
You will know when you look in the mirror if you are pleased with the look .

If you look at western movies the actors wore cowboy hats regardless the shape of their face. Think of the Marlboro man most of them had a square jaw.