The phrase "and so on/forth" is commonly used to refer to additional items or ideas that are not listed specifically. However, there are many synonyms you can use in its place, to make your writing more varied and engaging. For instance, you could say "et cetera" which means "and other things" in Latin. Alternatively, you can use "and such like", "and so forth", "and others", "and the rest", "and more", "and beyond", and "and additional". All of these synonyms convey the same meaning and can be used interchangeably in your writing. Experiment with using different synonyms for "and so on/forth" to make your writing more captivating.