Ten years ago, coffee was just a liquid stimulant - an acquired taste masked by more delectable milk and sugar. With the advent of gourmet coffee shops across the US, more people are expecting their Cup-Of-Joe to actually taste nice, not just stimulate. But it is often hard for newbies to replicate the taste of gourmet roasters at home, even when they buy gourmet coffee. Below are the most common mistakes I see people making (this of course assumes they are actually trying to make good coffee and that I really know what good coffee tastes like!). Later tips involve more investment and time.
By far the most common mistake is that people skimp on the amount of coffee that they use per cup of resulting in weak tasteless watery stuff. A good way to learn how much coffee to use for your coffeemaker is to buy Starbucks coffee and keep increasing the amount of coffee until it tastes stronger than Starbucks, then you know to use a little less than that amount (be careful, since Starbucks coffee tends to be very strong - too strong for me, but at least you’ll get a feel for the upper bound on how much to use).
If you want 1 mug of coffee (typically 2 cups), make 8-10 cups. In fact, always make >= 8 cups. Its much easier to get the balance of water/coffee correct when making a lot. This is the major advantage gourmet shops have over you. Just pour the left over coffee down the drain.
Leaving the pot on the warmer can turn the best coffee into rubbish in a short time. Coffee stays hot for quite a while if you make a bunch of it.
Whole bean coffee stays fresh much longer than ground coffee. A burr grinder is ideal, but a cheap twirly blade one will work if you are only making drip coffee. (If you like french press coffee, twirly blade grinders grind the coffee too thin leaving a gritty cup.)
Buying green coffee and roasting it yourself seems like a lot of work at first but is actually quite fun once you get the hang of it and doesn’t take too much time. Coffee goes stale approximately 1 week after roasting and only a few hours after grinding; green coffee stays fresh for years, allowing you to keep many different types of coffee and roast whatever you’re in the mood for. The best cheap coffee is about the same price as Folgers or Maxwell House though getting a roaster will cost a bit. Sweet Maria’s has tons of information on home roasting.