Use strong typing and early validation to handle optional values and prevent null-related issues. Prefer enums and specific types over strings when dealing with optional data, and validate optional values as early as possible in the data flow. Key practices: 1. Use enums instead of strings for known value sets 2. Leverage bool::then for cleaner optional handling 3. Validate optional data at structure boundaries Example: ```rust // Instead of struct Config { kind: String, // Could be "realm" or "index" value: Option } // Prefer enum ConfigKind { Realm(String), Index(String) } struct Config { kind: ConfigKind, value: Option } // Use bool::then for cleaner optional handling let value = condition.then(|| compute_value()); // Validate optional data early fn get_project_version(doc: &mut Document) -> Result { let project = doc.get("project") .ok_or(Error::MissingProject)?; let version = project .get("version") .and_then(Item::as_value) .and_then(Value::as_str) .ok_or(Error::MissingVersion)?; Version::from_str(version) }