title_body: What are the basic parameters that affect the flavor?
upvoted_answer: After some time has passed and no one answered, yet. Maybe I can come up with an answer. The question is not clear and if I understood correctly, the answer is too broad. Therefore, I will try to elaborate my answer by summarizing factors that effects the tag of the question.
  
  Note: Please leave comments as this is a quite broad answer.
  
  The species
  
  When we say coffee, we mention two different species of Coffea Genus. Coffea arabica and Coffea canephora (aka robusta). They have many differences. Shortly, Arabica grows in the mountains, more expensive and has more oil (so flavor), less caffeine. Robusta grows in the seaside, less expensive and has less oil (so flavor), more caffeine. More detailed discussion can be followed under this question.
  
  The origin
  
  You grow this plant in different places. Location and cultivation affects the taste. So, the origin has effects on the flavor. You may hear "Ethiopian arabica" or "Indonesian robusta" quite often.
  
  The blend
  
  So, it comes the blend. After the harvest, the fruits are collected, dried and the beans are picked. When you collect different beans from all over the world, you blend them. Sometimes, single origin beans are used to taste the flavor as it is. Sometimes, they are blended to mix the effect of a variety of beans. Blends may be all arabica, all robusta or mixed.
  
  The Roast
  
  After the blend is prepared, roasting starts. During roasting normally up to 15% of the beans weight is dried out. This process is one of the main decisions based on personal preference, blend structure and the targeted drink. A list of coffee roast varieties can be found here. Note that there are also unlisted very very light roasts as in green coffee.
  
  The grind
  
  Grinding is also closely related to the targeted drink. For example, the coffee must be as fine as powder for preparing Turkish coffee. On the other hand, such fine grinding is so unpractical in French press as the grains could easily travel through the filter.
  
  The Brew
  
  Choose a brewing method. As a subtitle, use proper equipment for that method. Master your brewing method. Needless to say, there are (probably) hundreds of them. I could enlist three main methods as: pressurized extraction, thermal extraction, and cold-brew methods.
  
  The service
  
  According to a questionnaire, baristas in Italy state that even pouring the espresso may affect the flavor. Apart from that, it is a known fact that the espresso cups must be pre-heated for a better experience. So, even serving the coffee is important.
  
  The freshness
  
  As a bonus article to the aforementioned ones, freshness. One should take car of the freshness of the coffee at each step. The beans themselves must not wait for years. After roasting, they should be degassed for two to three days before grinding. However, they should be consumed right after the grinding. There is a famous expression on that: the customer not the espresso must wait. In one experiment it is shown that, if one day old ground coffee is used, the foam volume of espresso is 35% less than the one prepared by freshly ground coffee.