Designing a logo for an established brand is usually a different experience than creating one for a startup company. An established company may know their target market, demographic makeup, and have the "personality" of the brand well documented. An aged company likely has an existing logo and desires a re-design.
A startup company, many times and understandably so, may still be developing their brand. A young business may still be working out the kinks in their brand identity.
Regardless, of when the brand was born, creating a logo is more than just creating a pretty graphic. Personally, I like to design logos that are expressive of the company and connect well with their customers.
There can be a great number of feelings and associations communicated in a logo. Even the colors are carefully considered. Everyone knows colors and shapes evokes many things, and different things depending on the context and perhaps even where it physically exists. Some cultures interpret colors differently.
Designers choose complexity and or simplicity appropriate to the brand. Creating a logo carries infinite choices, but graphic designers instinctively know what direction to take.
As a Los Angeles graphic designer, it always interests me to see the works of others and how their reality plays in the design of a logo.