Explain the two-pointer technique in detail, including its use cases, advantages, and step-by-step implementation. Provide [THREE EXAMPLE PROBLEMS] (e.g., 'Find pair with given sum in a sorted array,' 'Remove duplicates from sorted array,' 'Container with most water') with [OPTIMIZED SOLUTIONS] in [YOUR PREFERRED LANGUAGE]. Highlight common pitfalls and best practices for applying this technique efficiently. Use clear, concise pseudocode or actual code snippets to illustrate your explanation.