Life insurance is crucial for financial planning, providing security for loved ones in case of death. Common mistakes include underestimating coverage needs, delaying purchase, relying solely on employer-provided insurance, choosing the wrong policy type, failing to update policies after life changes, naming incorrect beneficiaries, allowing policies to lapse, and ignoring valuable riders. To avoid these pitfalls, it's important to assess financial obligations, purchase early, supplement employer coverage, and regularly review policies with an advisor.