When wills are being done in our law offices, we focus strictly on methods of distribution of whatever assets you own at the time of death (rather than using estate planning methods for tax reduction, for which you should consult an estate planning specialist). No one can predict the future regarding whether one might end up, (at the time of death), with $5 million or $5 in net assets.
An example of a typical formula for distribution of assets by a husband and wife (married for the first time) with 2 children would be that each spouse leaves everything to the other spouse, but if both die (for example, in a common accident) all assets are left to children in equal shares to be held in trust for such children until each is of an age specified by you (we normally recommend age 21). Until such age, the trustee(s) (named by you) can use funds for the education, health and welfare of your children.
NOTE: Of course, you can develop your own formula for distribution of assets since the above-mentioned formula is only an example. Wills can be changed any time (before death, of course!).