1. Start fresh
Beans are at their prime between two days to a week after roasting. (They start to taste stale by about 10 days.) Start at a local coffee shop that does its own roasting or brings in beans overnight. The roast date should always be marked on the bag.
2. Stop smashing. Start grinding
Most home coffee grinders have a single blade that smashes beans at high speed, so the resulting grounds typically range from fine dust to sandy chunks. A burr grinder creates uniform particles, which means you can control how sour or bitter the resulting coffee tastes. (See "Dial the flavour in," below.) Good electric burr grinders start at about $150, though you can get a decent hand-crank one made by Hario for about $32. Don't even think about buying pre-ground.
3. Scale it up
Is it ridiculous to weigh your beans and water on a gram scale? Completely. But it will also let you make a consistently excellent cup of coffee. A standard digital kitchen scale does the trick, though a pocket digital gram scale – there's a great one at Lee Valley for $16 – is even better.
4. Dial the flavour in
If you've followed tips 1, 2 and 3, try a slightly coarser grind, cooler water or longer steep time if your coffee is too bitter. (If it's sour, do the opposite.) You can also dial the brew's strength up or down by controlling your beans-to-water ratio: Between 12 to 18 grams of grounds per 260 grams of water is a decent starting range for a single cup.
5. "Piping hot" is overrated
Too much heat masks flavour and aroma and scorches taste buds. Give your coffee three or four minutes of chill time once it's made.