Start with 1 part coffee to 16 parts water. That's 20g of coffee to 320g of water for a single mug. Weigh your coffee if you can—scoops are too inconsistent.

After your first brew, taste and adjust:

• Too sour or weak? Grind finer or use a bit more coffee.
• Too bitter or astringent? Grind coarser or pour slower.
• Flat or dull? Check your water temp—it might be too low.

Don't change everything at once. Change one variable, brew again, and see what moves. It's like tuning a guitar—you don't twist all the pegs at once.