Ben suggests a pre-emptive option, 'Before lighting a candle, I rub a little petroleum jelly around the rim of the holder. Wax wipes away effortlessly later, leaving no residue.' However ...

I even trim my wicks! Which, by the way, you should be doing too if you want an even pool of wax. I’ve also done quite a bit of writing about candles and tested a bunch too. As a result ...

Containers must be heat-resistant – vintage jelly moulds ... Top up with wax if needed and maybe add a few dried flowers. Let ...