Every cloud has a silver lining... so even when I finish burning a wallet-weepingly expensive Diptyque (I call it Dippers) I don't mind too much, because then I can use it as storage. Same goes with any cute candles, or mugs. I like to display stuff on my dressing table :)
The little purple pot with cotton buds in it was once a yoghurt pot (a very fancy yoghurt pot, obviously), and the mug is just too pretty not to be displayed. The Bourjois candle now houses my cotton pads, which looks much nicer than the plastic wrapping they come in.
When I re-use candles, I pour boiling water into them to get rid of the wick/ any remaining wax and then leave it for a little bit to cool down. Using a sieve, I pour the water away, and then wipe the candle clean.
So even though I can't smell the candles anymore (sadness), I can look at the prettiness :) Every dressing table needs a Diptyque candle. Or two...