The phrase "of one's self" refers to something that is related to or originating from an individual. Synonyms for this phrase include "self-generated," "self-originated," "self-created," and "self-produced." Another option is to use the word "intrinsic," which implies that something is an inherent part of a person's nature or being. Other synonyms for "of one's self" include "personal," "individual," and "autonomous," all of which suggest that something is specific to a particular person and not influenced by outside factors. Using these synonyms can help to avoid repetition and add greater depth and nuance to your writing or speech.