1. What kind of wax do you use? Is it suitable for candles that are cast in molds? Is it suitable for standing (pillar) candles? You should read this information in the description of your wax or ask the seller / manufacturer if there is no such information.
2. What is the temperature of pouring the wax into the mold? Is it too low? Or are you overheating the wax? You must follow the recommended temperature for your wax. Try a lower and higher one than you are using and see the result. The temperature in the room where you are making the candle is also important. It shouldn't be hot or cold there.
3. Dyes and aromas. If the candle turns out to be bad with the addition of dye or aroma, then the reason is in it. Try a different type of dye or scent. You can test this by making a candle without dye and scent. If a candle without dye is good, then carefully read the instructions for the dye - often dyes are incompatible with some types of wax, or require a different temperature than the one with which you make the candle.
4. If you add too much scent, it will not all fit in the candle, and it will be covered with droplets.
5. The candle should cool naturally. It is unacceptable to place it in the refrigerator for cooling.
6. You should remove from the mold only a completely set candle - this can be understood by the fact that the mold is no longer warm.
Hope this tips will help you!
If you know something else, you can write it in this topic!