Before starting any design project, the first step is usually finding inspiration to begin the design planning. Some sites out there supply thousands of design inspirations for you to use.
Personally, I use Designspiration. A community driven site made for sharing designs found across the world and web. If you ever find yourself unable to think of a good idea for a design, take some time to look through what designs people are sharing. You can click on any design posted to be taken directly to the source, where you can then find even more design inspiration.