Ah yes. For me it starts with the blond hair/blues eyes of youth. So many have their eyes change color or hair darken as they age, which I find sad.
Not skinny. I've never been into twinks. Nor overly muscular. Just "normal" with a bit of plumpness here and there.
Younger, to a point, is better than older. Not that I would toss a boy out just because they started growing hair, but I would like to start while they're still baby smooth all over.
Summer is the time of lust. Above the knee shorts without shirts, or (dare I hope) a speedo at the beach/pool?
Full of fun and life. Unafraid to explore and try new things. But not so independant that they want to go it alone.
Never met him, but I dream.