Goblets are my nemesis. Every few years, I get requests for goblets or this time it was chalices for the church. I find them a real pain to make,,, and people dont want to pay what I want to charge. For the non potters let me explain. Each goblet has the cup portion and the stem and these are made separately but need to be put together and trimmed to look like one piece. Kind of like a marriage, maybe but I wont expand on that topic too long. The top and the widest piece of the stem should ideally be the same diameter to give the goblet balance, not only in appearance but for making it more stable.
The best tip I have received so far isn how to avoid them separating in the bisque firing. When you go to trim, the pieces should be workable, not quite leather hard. Score both sides really well, add a little slurry and adhere them one to the other while they are upside down on a coned piece of clay with wet newspaper on it.
Then roll out a coil the length needed to go around the join between the cup and the stem, and smooth that in to the piece until you cant see it. Now trim them together. I have fired goblets where I took the time to do this, and where I didnt. Completely different results. Worth the extra effort.
I am still not really happy with these, but they are getting better, still would like better balance between top and bottom, and for them not to look as though they have been drinking wine. (Tippy)