When configuring feature flags in Cargo.toml, ensure they are properly structured and documented: 1. **Chain feature dependencies correctly** - Features that depend on other features should explicitly list those dependencies: ```toml # Incorrect: cookie-signed = ["cookie-lib/signed"] # Correct: cookie-signed = ["cookie", "cookie-lib/signed"] ``` 2. **Document non-obvious configuration choices** with comments to help other developers understand your reasoning: ```toml # `default-features = false` to not depend on tokio which doesn't support compiling to wasm axum = { path = "../../axum", default-features = false } ``` 3. **Use appropriate syntax for conditional feature activation**, understanding special operators like `?` for optional dependencies: ```toml async-read-body = ["dep:tokio-util", "tokio-util?/io"] ``` These practices ensure that your configuration is both functionally correct and easier for other developers to understand and maintain.