What I find odd is when they offer a trade deal where they want a great work of yours but they are also offering a great work in return. The rest of the deal in these cases is usually horrible but what's the point? You're basically trading great works. Usually though they want my spare strategics and offer money and sometimes luxuries and great works which I take if I can afford it. But I end up rejecting more often than not or trying to haggle which usually ends up in a rejection anyway as the haggling rarely works out to anything good. I also hate when you just start collecting a new strategic resource so have only a handful and the AI wants all of it in a trade...pfft, rejected!