Understand the information you have
Identify your main records, where they originate, who maintains them and what decisions they support. Document common definitions so different teams mean the same thing when they use a metric.
Create a consistent structure
Use stable identifiers, clear field names and agreed formats. Separate distinct record types and define how they relate. Remove unnecessary duplication and record the steps used to clean or transform information.
Make quality an ongoing practice
Assign ownership, check for missing or inconsistent values and document changes. Good reporting depends on repeatable processes as much as it depends on software.