Soy candles should always have time to cure. The time will depend on the fragrance. Soy candles usually will get better with time too. However, there are plenty of fragrances that will throw with a short cure. I don't like to wait so I try to use only fragrances that don't need a long cure.
I will burn a candle right away when testing for wicks but when I am testing the fragrance, I give it a few days before burning. If it does not have a throw after a few days, I close it up and give it a few more days. If it still does not have a throw, then that fragrance is a no go.
Not all fragrances will throw in soy. If you are not getting a throw, give it time. If that does not work, you can try a different type of wick. If that does not work, then it is probably a fragrance that is not compatible with soy. Also, increasing and sometimes decreasing fragrance amounts can affect your throw.
Your selection of container will also affect your throw. Every fragrance should be tested. You might find that some of your fragrances will require a larger wick or a different wick all together. The testing process can be long and very expensive. If you change wax, jars or even fragrance suppliers, you must test all over again. Any changes to your candle and you can pretty much expect to have to test.
Not all fragrances are the same so, i.e. just because a lavender from one supplier threw well, you might find that a lavender from a different supplier might not throw at all or might require a totally different wick. Even the same fragrance but different supplier can change the way your candle burns and affect the throw.