1. I start by doing a competitive analysis of common and prominent firms/sites in the same vertical.
2. Review current patterns and trends. Pull ideas from major everyday sites like Amazon, Google, Facebook, etc...
3. Sketch ideas with paper and pencil.
4. Create initial wireframes and mock-ups based on requirements.
5. Work with project managers, business analysts and development to make sure requirements are met.
6. Review and iterate with client. Finalize with pixel-perfect designs.
7. Create style guides and/or red line docs for development.
8. Review and QA site to make sure all specs are met.