Outline your marital estate. Review your state's marital property division laws and consult with an attorney to figure out what assets are marital and which ones are separate. The law can vary widely from state to state, so what held true in a friend or family member's divorce won't necessarily hold true in yours. Once you've become familiar with the definition of marital property in your state, make a list of what you and your spouse have accumulated and who has possession of it now.
Figure out a value for all the assets you'll be dividing. Major assets, such as real estate or a business, may require an expensive appraisal by a property appraiser or Certified Public Accountant to arrive at an accurate figure. You may be able to find market values for other assets, such as cars, trucks and boats, by going online. Next to each asset listed on your inventory, put down a value.
List your marital debts. If a debt is attached to an asset, such as a mortgage on a house, write it down in a separate column next to the asset itself. Subtracting the debt from the asset value will show you the net value of that asset — what it's really worth. In some cases, you may owe more money on a house or vehicle than you can sell it for. In that case, whoever takes the asset and its associated debt will be receiving negative value when you divide the estate.
Negotiate with your spouse on who gets which assets and who takes which debts in order to arrive at your desired division of the marital estate. If one of you takes on an upside-down house or car, the other person will have to make up at least some of that difference in the form of cash or other property.
Set your property division agreement down in writing with your spouse, with both of you signing in front of a notary public.