At the end of the ritual, or do you blow out the candle or even put a glass to extinguish the fire?
Which love spell are you talking about?
The spell uses emotion and visualization and is similar to those EA wrote in Works of Darkness so, in my opinion, you should blow out the candle and, as the smoke rises, see it as bringing your vision to the universe.
I used this spell with sucess. I blew it out at tne end and then when i was with this person I light it again