When expressing the idea of something being even further or in a greater amount, the phrase "still more" can become repetitive and lose its impact. Therefore, it can be helpful to have alternative synonyms to vary the language used. Some options include "furthermore," "additionally," "moreover," "in addition," "what's more," "on top of that," "besides," "plus," and "to boot." These phrases can be used to emphasize a point or to provide additional information. By expanding your vocabulary and using various synonyms, you can improve your writing and ensure that your language is engaging and effective.