There are many mistakes that are made in developing your Estate Plan, but here are some of the most important: (1) failing to name a contingent beneficiary on wills, insurance policies, etc., (2) not reviewing your beneficiary designations on a regular basis, (3) naming your estate as the beneficiary of an IRA, which can lose tax breaks, (4) forgetting to remove your ex-spouse as beneficiary on an IRA or insurance policy, (5) leaving assets directly to a minor without naming a Guardian, (6) not having a Residuary Clause in a will, (7) having an imbalance in family assets, i.e. one spouse has much more in assets than the other. And the last two are related: (8) not dealing with your own mortality and what happens after you die, and (9) not planning at all.  You will be wise to begin planning now.