Wash and clean an ordinary soda bottle. Use Goo Gone if need be to remove the glue.
Put a rubber band around it...
...exactly 4" high all around.
Make a slit below the rubber band with your exacto knife. Or you can borrow mine.
Then using a sharp pair of scissors, follow the line of the rubber band evenly all the way around.
THAT was the hard part.
Fill the bottom of the bottle with sand. I actually keep a big storage tub of leveling sand on hand.
You didn't even blink at that, did you?
The cute little candles are from Walmart, 12 for $6.
Nestle your candle in the sand 2/3 in.
Now scatter sea glass and shells on top.
And we have the lighting for my son's graduation party! Well, some of it. Now, take the top of the bottle...