I'm working on a themed act and want to construct my own airborne tea kettle with tea cup. Any advice from anyone that has built their own similar effect? I have a very old version of the wine bottle and I'm sure there must have been improvements.

The wine bottle could give a sound if the weight hit the side of the glass. I owned a pepsi soda can version of the effect. The weight hitting the side of that would not really give off any sound. But I am sure you can control some of the sound by covering the weight with tape or something to get rid of 2 pieces of metal hitting. If you are on a stage then small amount of sound you make would not matter at all.

I think the tea-cup idea is great. You could add an extra dimension with the saucer... either keep the saucer detached and take it away to show the cup is floating on its own... or be able to show it detached but have a method to attach it so that both the saucer and cup float.

Post pics if you can.
I think this would be neat in an Alice in Wonderland Mad Hatter's Tea Party
Cups and Balls with tea cups

Yes, there were improvements to the Airborne Glass, I have a motorized version that cost $400 from Europe. For a cup, this would be most workable solution to your idea. I think you a Tea Kettle would be large enough to conceal the motor an battery.

Do to the neck design of Tea Kettles, I believe it would be problematic to use the old weighted method.

I see not reason why the original method would not work very well with a static line. Just have to find a light weight cup and find the balance point to offset for the cup handle not keeping it level.