The ratio

Coffee is brewed at a ratio of coffee to water. The standard starting point is 1 to 15 by weight: 1 gram of coffee for every 15 grams of water. From there you adjust. More coffee and the cup is stronger and more intense. Less and it is thinner and easier.

Most home brewers do not weigh anything. They use a scoop and a guess, which is why their coffee is inconsistent from one morning to the next. The scoop does not change, but the grind does, and so does the density of the bean, and so does how tightly they filled it.

A scale costs less than a bag of good coffee. If you are going to use good coffee, use a scale. The ratio is 1 to 15. From there, taste it and adjust. That is the whole system.