To dress candles
For this method it is best to use a non sulfur based, charcoal based, hexing powder. This is great for curse or protection candles (returning to sender). Simply dress your candle with a little Hexing powder along with your oils and herbs.
Barrier work, laying Hex lines
Laying Hexing powder across your doorway or windows is great for protection and returning malice. Sprinkle a little Hex powder by the door or on the window sills. When one lays a Hex line they do this to bring malice to a target. Pathways an enemy might walk are great areas to lay these. Simply sprinkle a line of powder where the target may cross. Sulfur based powder works nicely for these purposes.
In curse candle workings sprinkling a bit of charcoal based Hexing powder in the candle flame can send sparks and add a punch to Hexwork. Only use a powder that does not contain sulfur for this. Take care not to snuff the flame as you sprinkle.
Charcoal based Hex powder
To make a charcoal based powder, use charcoal partially burned for the purpose of loose incense. Coals leftover from incense burning work nicely. Mix herbs and spices into your coal. Only use plants safe for burning if you intend to use the powder for candle workings. Many baneful herbs are not safe to burn. Herbs with protection or exorcism properties, like mugwort, can work well.