Failure to regularly review your will. You should review your will with your attorney whenever there are major changes in your life, or every two to three years. Has the executor or some other person named in your will died, or become incapacitated? Are there new family members since the last will? Have your purchased or sold property?

Not having a power of attorney or healthcare advance directives. Without a power of attorney, simple tasks like filing a property insurance claim may become impossible. A property owner who suffers a period of incapacity, may find that without a Power of Attorney there is no one authorized to collect rent, or to institute an eviction action against tenants who fail to pay rent. And without advance directives, your final illness may not be managed as you had hoped.

Failure to name a beneficiary, and an alternate beneficiary on your insurance policies. Life insurance benefits are tax-free if they are paid to a named beneficiary. Otherwise they may be taxable, and sometimes, undesignated insurance proceeds can only be released after a probate process.

Not keeping copies of beneficiary designations . Your insurance policies, bank and brokerage accounts, IRAs, 401(K) accounts, and other assets will usually go to a specifically designated beneficiary irrespective of what your will says. But if the institutions holding those assets misplace the beneficiary designations, your desired beneficiaries may have a problem, and a costly one at that. Banks, insurance and mutual fund companies merge, or sell assets. Therefore, the burden is really on you to keep track of all your paperwork. When you send in beneficiary designations, always request that the company send you back an acknowledged copy of the designation.

Naming your estate as your IRA beneficiary, or failing to designate a beneficiary for your IRA . Such a mistake may mean that the IRA must be emptied immediately, with heirs losing the benefits of further tax deferral. Otherwise, even a nonspouse beneficiary may be able to stretch withdrawals of several years, adding thousands of dollars to the inheritance.

Assuming trusts are only for rich people. Your eighteen-year-old heir may be able to vote, or to serve in the military. But is she really ready to handle thousands of dollars. Some are, and others aren't. You can postpone the age at which she receives here inheritance by setting up a simple trust in your will. Name a trustee you can rely on to pay her income and to invade the trust principal for her only when necessary.

Failure to leave a letter of Instruction. When someone dies, that's when loved ones are least in a position to go searching for assets and important legal documents. This also is the time when individual feelings may be raw and closest to the surface. Sudden disputes about Dad's intent or what Mom would have wanted can permanently split families. The letter of instruction ties up your entire estate plan in a way that reduces the likelihood of family squabbles, and assures an orderly transfer of your assets.