There are several synonyms for the phrase "help oneself." One alternative phrase is "serve oneself," which is commonly used when referencing a buffet-style meal. Another option is "take for oneself," which can refer to taking food or drink from a shared container or taking advantage of an opportunity. "Take matters into one's own hands" is a phrase often used to suggest that one should take action without relying on external help. "Be self-sufficient" is another phrase that carries a similar meaning to "help oneself," implying independence and a lack of reliance on others. Overall, these synonyms suggest a similar concept of taking action and being proactive in solving one's own problems.