When going into the coffee shop business, it is important to have good personal taste regarding food and drinks. Without it, you will either make bad product decisions or rely heavily on others to make product decisions for you. This is not the end of the world, but does require that you trust not only the ability of your partners or employees, but that they are putting your interests first.
If you know you are lacking in the area of taste, you can take a course in coffee appreciation or work on your own to learn the many different tastes of coffee, tea, and other beverages available. Developing the ability to compare the tastes of drinks made by your potential competitors will improve your chances of competing successfully once you open.