Examples of assets you may mis-value: The Family Residence; Mutual Funds/Stocks; Tax Deferred Investments. Whether or not you can reasonably argue that you should take post tax value as the value to use for percentage shares at the division of asset's stage often depends on how soon an anticipated sale will take place. In any event, you should at least have the "true" post tax values in mind when deciding what is a good deal for you.
Note that the below references to taxes is not intended to be tax advice. Taxes laws change over time and your own tax circumstances may make the below not applicable to you. Always consult a CPA.
Sale of Family Residence
When you think about keeping the house in the final settlement, are you thinking about the market value of the house, or are you thinking in terms of what the house is worth after real estate agents fees, attorneys fees, escrow fees, excise sale tax, etc.? Capital gains taxes on the sale of the primary residence are usually not a substantial problem now for many of us but always check with your CPA to see if YOU owe capital gains. At this time an individual is allowed a $250,000 gain exemption on the sale of their primary residence and couples are allowed $500,000. Again, check with your CPA to see how your "gain" is calculated. Note that when you take the house in a divorce, you take the "basis" too. The "basis" is the cost of the house. Consult with your CPA about how "cost" is calculated and don't forget to include the improvements. The IRS looks at this when considering how much gain you have on the sale of your house. Capital gains on a family residence is often not applicable now that the exemption is so high. Nevertheless it can affect some e.g. if you take the house in the divorce, and lets say you bought it many years ago for a comparatively little sum and is now worth a small fortune, you may be looking at a gain of over $250,000, the single person's gain exemption. So YOU pay capital gains on the excess. All of the foregoing considerations can result in a sizable chunk out of the value of the house.
This is a good moment to mention a tax trap: Be careful that you are not out of the family home too long to qualify for the primary residence exemption!!
If you sell these for a profit the IRS will want to tax you on the gain. You may have paid some taxes over time on these investments. You don't want to pay the same tax twice. In addition make a careful note as to which are short and which are long-term gains as this affects the tax. It is a good idea to consult your CPA regarding a tax estimate on these assets so you can assess their true worth before you decide which of these investments you want to take in the divorce.
Tax Deferred Investments
As for tax deferred investments, how are you calculating their value? If one cashes these out prematurely for immediate cash, you can be subject to a 10% penalty fee and immediate calculation of taxes on that investment. This also results in significant diminution in the value of that asset. The old adage that cash is kind is very often the case in a divorce situation.