FWIW I just started to “contribute.” The quote marks are because I have no way of knowing what value judgments anyone else has. But I’m centering / cropping images at the Art Director webpage.
My thought is that if Roon doesn’t want this to be haphazard affair, a few basic photo editing “best practices” might be published. Such as don’t “cut off” limbs at joints when cropping. It’s OK to crop “though” foreheads or forearms … our brains naturally fill in the missing parts. Maybe try for a rule of thirds perspective for banners.