I enjoy the ambiance of a candle, but as with all open flames precautions must be taken. Keep them away from curtains and other flammable materials. Always use an appropriate candle holder. If you have a candle on the toilet tank, place a coaster or pot holder under the candle holder; the heat from the candle and cold from the tank may cause the holder to break. This is a note from personal experience; thankfully the candle went out and no fire resulted.
If leaving the house or if pets are present, be extra careful. This also applies to children; playtime can quickly turn into emergency room time if precautions aren't taken. Use the candles responsibly and enjoy their beauty and relaxing effects.