Act as a senior database administrator with 10+ years of experience optimizing SQL queries for high-traffic applications. Provide a detailed step-by-step guide on how to improve the performance of [DATABASE_TYPE] queries, specifically for [USE_CASE]. Include best practices for indexing, query restructuring, and execution plan analysis. Address common pitfalls like [COMMON_ISSUE] and how to avoid them. Use real-world examples and benchmarks to illustrate the impact of each optimization technique. Ensure the advice is actionable and tailored for [SKILL_LEVEL] developers.