To prevent emails from landing in Gmail's promotions tab, various strategies are suggested. Some marketers emphasize the importance of valuable and personalized content, consistent sending habits, and encouraging subscribers to move emails to their primary inbox. Authentication methods like SPF, DKIM, and DMARC are also highlighted, along with cleaning email lists. Enhancing email engagement through compelling subject lines, audience segmentation, and personalization is recommended. Avoiding promotional language, spam trigger words, and warming up IP addresses are also advised. Others recommend building relationships with subscribers and using a dedicated IP address for large email volumes. A/B testing emails is also suggested to improve engagement.