The Hoffman recipe is 12g of coffee, 250ml of water, 2 minutes steep time, give a small swirl to the recipient, steep another 30 seconds, then press down slowly over at least another 30 seconds. You can find the video on youtube.
There are many other factors involved such as the size of the grind, the uniformity of the grind, the temperature of the water, the steeping time, and the quantities of coffee and water – so really the recipe is just meant as a starting point. You will need to dial it in for each different batch of coffee.
Most of these factors have to do with caffeine extraction aka “yield”. More time steeping, hotter water, more water & coffee and finer grind all increase extraction but in different ways, and over-extraction usually ends up tasting bitter. The opposites decrease extraction and under-extraction ends up tasting sour. The Hoffman recipe is a balanced start.
With the Aeropress you have easy access to all these factors and can customize the brew extensively but you have to do some trial and error.