"And what's more", a commonly used phrase to emphasize a point or add additional information, can be replaced with a wide range of synonyms. Some of the most suitable alternatives include "furthermore", "more importantly", and "in addition". Other options include "moreover", "not only that", and "on top of that". Using these synonyms can help grab the attention of the audience and highlight an essential point. They create a more engaging and persuasive style that keeps the readers interested. When used appropriately, these synonyms enhance the flow of the text and clarify the writer's message.