There was a week with awful winds at IAD and at several other airports in the vicinity. I flew IAD-ROA and back twice that week, and both times "enjoyed" some of the worst turbulence I've ever experienced.

On the last flight, the FA waited until we'd climbed into relatively calm air before beginning her service. She got about halfway through the little SF3 before we got slammed several times, and she had to literally brace herself on the floor in the aisle to keep from being thrown across the plane.

She handled it all very well, and told us later that it had been that way all week (which I believe, based on my earlier flights that week!).

No panic from her or from the passengers. Professional attitudes really seem to help in situations like that.