1.  Placing property or accounts into joint tenancy with a non-spouse. Banks do this all the time when all you want is to be able to help Mom or Dad with a bank account - without telling you!

2.  Failing to make out a will AND destroy any old wills.  I have seen wills prepared by clients on their own with commons software which have created inherent conflicts in the documents!!  Please don't "try this at home".

3.  Failing to make out a durable power of attorney AND living will.  (Terri Schiavo).

4.  Failing to execute a funeral wishes declaration (Anna Nicole Smith)

5.  Failing to keep beneficiary designations current.  Those expensive (and often unnecessary) trusts prepared by other attorneys to avoide probate are useless if your accounts are not payable to the trust or another beneficiary.

6.  Signing an Affidavit of Common Law marriage to get health insurance benefits.  If you are common-law married for a minute, you remain married until you go through divorce.  There is no common law divorce!

7.  Entering a second marriage without a prenuptial agreement.  Your new spouse can inherit all your property, then leave it to his or her family - cutting your family out.

8.  Failing to review your estate plan with an estate planning attorney during and after a divorce. 

9.  (a) Co-signing/guarantee of debt (b) loaning money without a proper promissory note or collateral.

10.  Hiring a contractor without a written agreement.