This three-part series on estate planning mistakes highlights common errors undermining estate plans. Part 1 focused on jointly held property issues, insufficient liquidity, and executor selection. Part 2 covered marital deduction pitfalls, strategic asset distribution, business continuity, and modern family dynamics. Part 3 details further crucial mistakes including incomplete client information, poorly coordinated estate instruments, poor communication of the plan, incorrect beneficiary designations, outdated plans, overreliance on joint tenancy, insufficient disability planning, failure to account for blended families, and reliance on informal arrangements. The ultimate goal is to help clients and planners create effective, comprehensive, and harmonious estate plans.