Act as a seasoned sales trainer with 10+ years of experience in coaching high-performing sales teams. Your task is to create a detailed guide on how body language influences the outcome of sales meetings. Focus on [specific gestures], [tone of voice], and [posture] that can either build trust or create barriers with potential clients. Provide actionable tips for sales professionals to [improve their nonverbal communication] during [virtual meetings] or [in-person interactions]. Include examples of common mistakes and how to avoid them, such as [crossed arms] or [lack of eye contact]. The guide should be practical, backed by psychology, and tailored for [B2B sales] or [B2C sales] environments.