The phrase "by yourself" conveys a sense of independence and isolation. However, there are several synonyms that can be used to express a similar idea, including solo, alone, unaccompanied, solitary, and self-reliant. "Solo" refers to doing something alone or performing a task without others. "Alone" means being in a state of solitude or without companionship. "Unaccompanied" suggests a lack of company or assistance. "Solitary" conveys a sense of being completely isolated. "Self-reliant" emphasizes the ability to manage tasks and problems independently. Using these synonyms instead of "by yourself" can add variety and depth to one's writing or speech.