I make soy wax candles in tea cups and glasses that I generally buy in charity shops. I love this kind of “upcycling” and it means that I never know what kind of candles I’ll be making next. Also, everything I make is one of a kind (or only one of 4 or 6 if I end up with a set of tea cups!).
Soy wax is a natural product, so it’s better for burning in the home. It also doesn’t produce the soot that paraffin candles do — I’m sure you’ve burnt a candle and noticed the black soot staining the top of the candle container after it has burnt down a little. I also use soy wax to make floating candles and scented wax melts for use in burners. The great thing about soy wax is that, because it’s natural, the candle containers can be reused when the candle has been burnt, as long as it has been washed in hot soapy water!
I’ve also been experimenting with making rolled beeswax candles. Beeswax is another natural product, and burns more slowly than other types of wax. It also gives off negative ions as it burns, which trap allergens — so it is thought that burning beeswax candles during the summer can ease hayfever. (And that’s all I know about the science of it, so please don’t ask exactly how that works!)