I have to agree, how it is done is not what you would first suspect... at least for the first two phases of it. Once you see how it is done, you WILL do the requisite head-slap. It is in fact, very logical. In regards to performance, I definately would not recommend doing it outside, on a bright, sunny day. In this case, at the very least, you want to do it in the shade. Ideally, it should be done inside, with hopefully lower than average lighting, (your usual bars & resturaunts fit this bill in most cases). And, if the libations are flowing amongst your spectators, the more the merrier!
Personally, I would use this as an opener, and then immediately segway into other ring-based magic and/or the rest of your routine. Done right, it is a strong effect worth exploiting, just as soon as it establishes the "suspension of disbelief" in your audience. In the few minutes it takes to perform, you will have them believing you are Gandolf, reborn, in the flesh. Use that advantage to it's fullest!
This effect is fully achievable by beginners and advanced "wizards" alike. Of course, the more advanced will see the possibilities beyond this, alone. It is very simple in principle. But, pregnant with potential!!!