Folded arms are a real trick to draw, I'll say that. Sometimes it helps a bit to cheat at it.

But, for a basic start, you've gotta judge a bit where the elbows are going to end up. I think that's the main problem with what you've got there, the guy's elbows don't drop down far enough before the arm goes back up.

Besides that, I think the only other major thing is his arms narrowing a bit as they go on. :-)

Anyhoo, yeah, folded arms are a fairly complicated thing to draw. Don't take it hard.