Sixty grams of coffee per litre of water, and everything else is adjustment. Weigh the coffee, weigh the water, and keep one of them fixed while you change the other.
Start with 15 g of coffee and 250 g of water at 94 °C. Pour 50 g, wait forty-five seconds for the bloom, then pour the rest in two even additions. The whole brew should run out between two and a half and three minutes.
Too fast and thin? Grind finer. Too slow and bitter? Grind coarser. Change one variable at a time and write down what you did — the notebook is the actual technique.