Good Terraform modules save time. Great ones save your sanity. Here's how I structure modules that teams actually want to reuse.
Module Structure
A good module has: Clear inputs (variables), clear outputs, single responsibility, documentation, examples. Keep modules focused on one thing.
Naming Conventions
Use consistent naming: resource-name-component (e.g., aws-s3-bucket, aws-ec2-instance). Makes modules easier to find and understand.
Documentation Matters
Document every variable, every output, every assumption. Include usage examples. Future you will thank present you.
Version Your Modules
Use semantic versioning. Breaking changes get a new major version. This prevents accidental updates from breaking everything.
Want to build better Terraform modules? Start with clear inputs and outputs, add documentation, version everything. The rest comes with practice.