I think almost everyone here will say "plain glass" for regular wine glasses. That may not hold true, however, for dessert wines. It would not offend me, for example to drink madiera, port, ice wine, etc... from a small glass with gold decoration. In fact, our hosts at a small winetasting party served their 1875 madiera from small glass with substantial gold inlays. Very impressive.
As to slight variations that demonstrate that these are hand blown, I would think that would not be a problem at all. Charming actually.
If you want to see a large number of glasses, decanters, etc. you should check out the wine enthusiast catalog on-line, which has a section on wine glasses, and one on decanters. It is:
http://www.wineenthusiast.com/templates ... CCEE770A28
You might also think of making glasses for wine tastings. Perhaps someone here can point you to the wine tasting glass that is stemless, but not like a Riedel O glass.
And for decanters, I don't recall seeing any designed for double decanting, with a pouring lip or spout to pour the wine back into the wine bottle.
Good luck. Let us know what you come up with.