Wear a dust mask, cause' glass powder isn't good for the lungs. Eye protection is always a good shot too!
Step 1: Pick a Bottle
Check this size bit. I choose this shape to go in at a slight angle so it is more like you are digging out the glass
rather than wildly spinning through it like on a drill press or the like.
Step 2: Start to drill, baby!
Begin drilling at an angle.
Step 3: Continue With a finer point bit to penetrate the bottle.
Step 4: Round out the hole to dime size.
Step 5: Get Your Incense Ready!!!!
let weighted part dangle on the outside of the bottle (it is generally good to make the weight out of something larger than the bottle opening. (so your whole deal won't fall into the bottle)