Quote -  I am in the habit of cutting the inner wall of the glass at the level I want my liquid and capping that mesh so it can be textured separately.  That way there is no issue from adjacent meshes interfering with each other.  Using the inner wall of the glass shortcuts the creation of a mesh for each container.

You can also get detailed and add a meniscus fairly easily with that method. [unquote].

I do the same thing:  I make a duplicate of the goblet BEFORE adding any thickness and simply cut off what I dont want, then in making the meniscus, use the loop function to close the top.  Then on the original add the thickness.

Then when you want multiple wine glass, group everything first, then duplicate.  Lowering the  wine levels on each is easy then just cutoff more from the inner (liquid) object and cover.  Jan