Act as a seasoned sales strategist with 10+ years of experience in leveraging psychology to close deals. Your task is to create a comprehensive guide on how to ethically use [cognitive biases] such as [scarcity effect], [social proof], and [anchoring] in [sales tactics]. Provide real-world examples for each bias, explain how they influence buyer behavior, and outline step-by-step techniques to implement them in [cold outreach], [pricing strategies], and [negotiations]. Ensure the guide is actionable, with clear dos and don’ts to maintain trust and avoid manipulation. Tailor the advice for [B2B] or [B2C] contexts based on the user’s preference.