Candles in water

I have a question about candle setup. I like to put my candles in a dish of water (usually like a pie tin) because I leave them burning. What should I do for this in terms of when I place a petition under the candle, or place a conjure candle on the seal? Is it okay to still put the candle in a water dish and then sat the petition or seal under that? I’m not trying to burn my apartment down over here.