What is important to keep in mind when designing a database?

I don't want to limit your answer to my needs as I am sure that others can benefit from your insights as well. But I am planning a content management system for a multi-client community driven site.

When designing a database a what is an important consideration?

The information requirements are the most important part.

What is the most important element of database design?

The table is the most fundamental element found in a database schema. Columns and rows are associated with tables. Tables, columns, and rows are discussed in the following subsections.

"Normalize till it hurts; de-normalize till it works."