When a function can determine an early result based on input validation or special cases, return immediately rather than assigning to a temporary variable and having a single exit point. Early returns reduce nesting, improve readability, and often result in more efficient code by making guard conditions more visible. ```c // Recommended: static int convert_prio(const int prio) { if (prio == CPUPRI_INVALID) return CPUPRI_INVALID; // Continue with normal processing return prio - 40; } // Avoid: static int convert_prio(int prio) { int cpupri; if (prio == CPUPRI_INVALID) cpupri = CPUPRI_INVALID; else cpupri = prio - 40; return cpupri; } ``` Early validation helps prevent unnecessary operations when preconditions aren't met, and results in flatter code that's easier to understand and maintain. Using `const` for parameters that won't be modified also improves code clarity and can help the compiler optimize.