I've never heard of anyone tipping a TA with cash (it may happen, I don't get out much!), but many people bring them a gift after their cruise. If you know of something your TA likes (mine loves trying new wines), I think this kind of gift would be better than cash. My TA has also gotten flowers, fruit baskets, etc., but I think she likes the wine best! Some people bring souviners from their cruise, but really, she goes on so many cruises herself she has all the souviners she needs.