Suit oneself is a popular phrase that implies a person's decision to do something according to their own preference or convenience. Some other synonyms that can be used for this phrase are "please oneself," "do as you like," "follow one's own fancy," "indulge oneself," and "do what one wants." Essentially, all these synonyms signify a person's right to make their own choices and decisions without the influence of others. These expressions are commonly used in various settings, such as in social situations, at work, and in other personal situations where people assert their autonomy. Ultimately, the phrase "suit oneself" is just one example of the importance of individuality and personal freedom in modern society.