Through wills and trusts, you can distribute your property, money, personal possessions, and other assets, making sure they go to the people you choose. You can make sure survivors have adequate care, and you can designate guardians for any minor children or dependants.

Leaving too much to a spouse. Leaving everything to your spouse is by far the simplest choice, but may not be the best for at least two reasons. First, if you have children, you'll lose control over what happens to your assets if you bequeath them outright to your spouse. She could very well leave everything to her next spouse, for example, or the con man she becomes devoted to after your death.

Secondly, if your estate is large you could be losing a valuable tool for minimizing taxes. Putting at least some of your wealth into a bypass trust will allow the assets to grow, and eventually go to your heirs, without triggering a second round of estate taxes on your spouse's death.

Not leaving enough to a spouse. If you live in a common-law state -- and 41 states are, as well as the District of Columbia -- you can't disinherit a spouse. You typically must leave him or her one-quarter to one-half of your estate, depending on the state's laws. Even if you live in one of the other nine community property states (Arizona, California, Idaho, Louisiana, New Mexico, Nevada, Texas, Washington and Wisconsin), your spouse may have certain rights to your estate. In California, for example, a surviving spouse can claim all community property, as well as a share of the dead spouse's separate property, if the will or other estate plan was made before marriage and not updated to include mention of him or her.

Improperly disinheriting a child. In only one state -- Louisiana -- does a child have a right to inherit by law. In the other states, though, a child has a good chance of getting a share of the inheritance if she isn't mentioned in the will at all. If you really want to disinherit a child, mention him or her by name in the document. Try to resist the urge to add unnecessary comments about that person, however, since that will create even more bad feelings and raise the possibility of a will-challenging lawsuit. Another approach: Leave the child something of value, with a "no-contest" clause that revokes the bequest if he or she challenges the will.