There really isn't a ratio that I can promise will always prove to be effective. Unfortunately I've never worked with pure beeswax for candles so I can't give you any experienced input on the particular wax you're working with. I can tell you from using soy and a few different types of paraffin wax that USUALLY I use 1oz FO to 1lb of wax. There are a lot of factors to take into consideration though, the type of wax, the type of fragrance oil (not just the scent but the source), how strong you want the scent, and so on. Hopefully someone with a bit more experience with beeswax candles can chime in, in the meantime, can you tell us where you got your Citronella oil from? It might help save time later if one of our beeswax candle makers know that in advance. I hope you enjoy candle making as much as the rest of us do. Starr