The Secret Recipe
Healthy plants, proper environment all day and night from day one till finish that mean lighting and environment, proper irrigation and nutrient practices, no bugs, wilt, pm, no decencies, knowing your strain, nutes, and equipment. Proper maintenance pruining, cleaning, cloning and ipm. Proper veg times proper plant placement.
Not taking short cuts, using band aides or rushing anything.
Genetics play into also but isn't luck or a gavita, or a box of rockwool it's every little thing every day.