How can I make sure to get the best n m9st out of ...

Best is a relative term, there are several things that when properly dialed in will improve your grow quality. Environment, meaning both temperature and humidity; while the plant will grow in a wide range of both temps and RH, if you keep them in the optimal range you will notice a healthier plant with more resin and higher THC content. For example temperatures below 23°C (73°F) will make your plant growth slow down to a crawl, above that point, the growth speed explodes; although temperatures above 26°C (79°F) will degrade thricomes. With humidity, specially in flower, if you keep it low enough (40% to 50%), your plant will produce more resin and reach its THC potential. Watering (in soil): giving just the right amount of water is of upmost importance, which is why learning to transplant is so important, because keeping the plant in a container appropriate for its size will limit the amount of water you give it to the amount that's best at that point; later, when you know how much your plant needs at what stage, you can just start it in their final container. I follow this rule for watering, I start with a cup of water, which lasts the plant 4 to 5 days, as the plant grows, the cup of water will lasts less and less, when it lasts only 2 days, then you double the amount, which will again lasts 4 to 5 days, rinse and repeat doubling the amount previously used. Training, the objective behind all kind of training techniques is to create an even canopy, learn to LST, TOP (of FIM) at the very least, super cropping can be really helpful for stretchy plants like sativas or in emergencies when running out of vertical space. Always measure and adjust pH, even in soil. Having (and using) an EC/PPM meter really helps in dialing in the feeding strength. Personally I prefer to let the plants feed on the soil and only start feeding when I spot the first signs of deficiencies: a small deficiency will not impact yield, bad a nutrient excess or worst a nutrient burn can be disastrous. Keep a log of what you do, your temperatures, your humidity, your feeding strength, it will help you learn and help in future reference in other grows. Don't be hasty, a proper cure brings out the subtle taste and smells of your buds. Hope I could be of help.