Be Honest About Your Body
It's the 21st century — if you want to let it all hang out, you're free to, at least as far as the local laws permit.
That said, some realistic expectations about who wants to see your naked flesh, and how much of it, go a long way. A little self-consciousness is not a bad thing. Ask yourself a few questions regarding your body:
Are you a little soft around the middle? Two schools of thought here:
For the modest man, trunks are your best option. A looser cut will balance things out. Avoid boardshorts or a strongly-elasticized pair of trunks that dig into your belly. Also stay away from longer inseams, as they'll pull your trunks down when you walk. Look for a shorter cut in a non-attention-grabbing color.
For the confident large man who prizes comfort, consider swim briefs. Yes, many of you might think this is a sight others don't want to see, but realistically this will be the most comfortable option physically. They don't slip down and will conform to your body. Mentally, though, are you confident enough to let it all hang out? I've been to European beaches — over there swim briefs are not a big deal. Stateside, you'll need a bit more confidence.