This study presents a refined and empirically validated set of guidelines to support communication practices in project management. By integrating theoretical foundations with feedback from 18 experienced professionals, this research reinforces the importance of cultural awareness, tailored strategies, and adaptive practices in modern project environments. A two-stage empirical protocol, survey and expert workshops, was applied. Results demonstrated excellent internal reliability (Cronbach’s Alpha = 0.91), and IRR values ranging from 0.78 to 0.94. The final output includes both comprehensive and streamlined sets of 32 guidelines categorized into three dimensions: communication infrastructure, stakeholder communication, and communication with end users. This framework helps project managers align expectations, improve clarity, and foster engagement, ultimately contributing to improved project outcomes.