If you make your own candles, and like the idea of having them be as attuned to your workings as possible, here’s something to try: 

Color your candle using extracts from plant (and/or other) material that coincides with the intended working. I don’t mean simply add herbs to the wax, I mean creating your own coloring agent for the wax by extracting it from appropriately aligned material components. This will, undoubtedly, make the entire operation of making the candles more laborious, and probably only makes sense for creating lots of single-use candles (such as votives or tealights) you know you’re going to use, but it’s my hypothisis that this could make the candle that much more magickly potant.