There are many synonyms for the phrase "once again" that can be used to convey a similar meaning. Some alternatives might include "once more," "repeatedly," "afresh," "over again," "anew," "another time," "recurrently," or "back again." Choosing the right phrase will often depend on the context in which it is being used, as well as the tone and style of the writing. The use of creative synonyms can also help to add variety and interest to a piece of writing, while avoiding repetition and monotony. Regardless of the choice of phrasing, the key is to clearly and effectively communicate the intended meaning to the reader.