Welcome - Candlemaking is a lot of fun, especially once you get the hang of it. However like shunt said, it does take quite a bit of time to test everything thoroughly enough to be ready to put it out on the market.
The inconsistencies that are out there are mainly with soy. I don't work with soy so I'm unsure exactly what they are, but I know that it is affecting a large majority of soy candlemakers.
My best advice, pick a type of candle you want to make - pillar, containers, votives, whatever, but pick 1, then 1 mold/jar, and pick a wick series and just start testing, unscented, uncolored, changing out wicks or wick series until you get a candle that you think burns great. Then once you know how the candle is supposed burn consistently, then you can start adding your variables such as scent, color, etc., If you do that, it will be easier to diagnose when a candle doesn't burn correctly, you will immediately know what needs to be changed. This will also help you test faster when you introduce different waxes (if you want) and different molds/jars, etc.
Hope this helps, and welcome to the addiction.