The crew on-board can usually do a great job of taking care of special carry-ons.

Sometimes it's in an obvious way -- some UA equipment (757, non-TED A320, 767) has closets.

Sometimes it's a little more tricky -- there's space to hang coats behind F on the A319 and the ex-TED A320, and I'm sure the crew could find some room.

And sometimes it's just creative -- I've seen stuff travel in the cockpit.