The visual essence of your business
It's your name! It needs to be distinctive, easy to read and capable of going from very small sizes (like on a business card or web tile) to quite huge dimensions (like on a billboard). It should work in black/white or full color. It also needs to resonate with the consumer. It is like crafting a suit. It needs to fit perfectly and enhance your business. It is the first thing people will see - usually small and on that business card that I just mentioned.
I have done many. Usually I approach it by doing many variations - usually 20 or so to get an idea of what the customer prefers or likes and respond to. I also do market research to see what your competition is doing and how they stack up. It becomes a lot of blending ideas and coming up with something to make everyone happy. It is the most subjective and the most scrutinized area of art.