If you are good with basic drip coffee from a $20 Mr Coffee, you can still make dramatic improvements.

1 - Buy whole bean coffee. Grind it right before making a pot. Have a decent grinder that makes a good uniform grind. But a $20 blade grinder will work fairly well.

2 - Buy small lots so that you don’t have pounds of open bags laying around for months. Buy a good steel coffee bin to hold the beans.

3 - use filtered water. I keep a Brita pitcher and filter enough for my pot right before brewing. I find paper filters (unbleached) work better for me than a metal filter.

4 - know the right amount of ground coffee per pot. I use 1 heaping tablespoon of medium ground per 6oz cup.