The variety has to be endless.
For the US service,
A white hat could be worn several ways.
Perfectly round, squared, commode rolled,
tipped to the front, side, back or centered.

Or a sailor could wear a duck billed hat, a watch cap or in the winter if you were lucky enough to have one, a Korean War army winter hat.

Many wore non-regulation Wellington boots, tailor made surge fabric dress blues that were non-regulation. But those who had spent some time in the Orient had them and wore them on liberty.

Even the officers' dress varied. Occasionally, an officer would show up for inspection with a very off white uniform, which was an expensive tailor made uniform.

Then there were the mustangs, conspicuous by their left over enlisted men dungarees that they wore. Officers, who had not been enlisted men, never wore them.

I can only assume that sailors worldwide wear their uniforms in a variety of ways.

But when it comes to movie actors riding a horse that is a different story.
Did you see Jammie Foxx throw the football in the movie "Any Given Sunday"? He looked like he knew what he was doing. Guess what he broke a state high school record for yards thrown in a single season.
Or when he played the piano in Ray. He won a college scholarship for music as a concert pianist.