Scent throw is also an area I'm working on. I started using 3% as the FO's are so potent, and 3% gave a nice cold throw (I didn't want the scent to be "punch your eyes out" strength when you put your nose to it). I thought the 3% gave me as good hot throw as the paraffin candles I used to buy (mid price), being that I can smell a whiff of it every now and then when I'm within 4 meters of the burning candle. However, having smelt the Diptyque candles recently at a friend's place, I'm working on improving the scent throw to be able to fill an entire room. I've just increased the FO to 6%, and in my opinion, has not really improved the hot throw. I also preferred the cold throw of the 3% FO candle. So I'm not sure what other variables to change now. It's easy to make a NICE soy candle, but freakin hard to make a GREAT one!