What is a good technique for drilling holes in glass bottles?
This can be done, but the difference can have more to do with the type of glass than the method. From personal experience, tempered glass is inherently stressed and is almost impossible to work with. Areas towards the necks of bottles have similar issues.

I suggest fresh masonry bits for their cost effectivenss. Too slow can cause stress from the pressure of the bit, too fast can create too much heat. Keeping the work cool and lubricated is easy in this case (water).

I have even had some success using a HSS drill bit run in reverse (suggestion from my father). Although, this tended to produce a rougher hole.

To be intricate and fancy (aka small and detailed) I would opt to using something like a diamond burr in a handheld rotary tool, like a dremel.

Let us know how it turns out!