Okay - going to address a few popular candle trends - but with an eye for safety!
First up - extras in your candles (e.g., herbs, flowers, fruit, foods, metals, plastic embeds, etc.). I avoid adding these to my candles because of a little phenomenon known as "secondary incineration". This is where the items floating in the wax can actually catch f...ire. This is easy as they are soaked in melted/liquid wax, hot, and there is an open flame - like RIGHT there. These items are for aesthetic value to be honest and do not add to the scent. This is why we advise that you clean out old burnt wick pieces from your wax and even little insects that sometimes get caught in there.
I am guilty of adding glitter, shimmer and sprinkles to my candles and there has never been a problem with these items.
BUT I decided to test! Who set sprinkles on fire just to check? Me. Under the watchful eye of a boyfriend who is a trained chemist. Those things BURN. Didn't smell good either.
So shimmer and glitter stay. YAY!
I have LOVED adding lavender buds to wax in the past as well as sprinkles - and have stopped. Pretty, I know. But until the laws of physics and chemistry change...