Trying to create a conflict-free estate plan is difficult, and it's not just the plan you have to think about. Sure, it is important to avoid potential conflicts over issues like unequal bequests or the division of sentimental assets, and you need to keep that in mind when drafting your plan. But it also goes beyond that.
What you really need to think about is why adult children don't get along with each other in the first place. The family dynamics are very important. Often, these conflicts really come to a head during the estate administration process, but that does not mean they're new. They could have been lurking beneath the surface or even overtly influencing your heirs' relationships for years. They just become more obvious when there is money on the line.
For instance, your children may deal with sibling rivalry. When they were younger, it manifested as a craving for attention. Children who felt they didn't get as much attention -- the cliche middle child, for instance -- may have felt that you didn't care about them as much as their siblings. You can also have rivalries between older and younger siblings as they try to figure out their place in the family.
As children grow into adulthood, the obviousness of this rivalry fades because they start living on their own and having their own lives. That does not always mean that it ends. You just don't see it on a daily basis. It can come back when they have to sort through your estate.
For instance, children who feel that they did not get treated fairly when they were young often resent other children who get more. If they then think that the estate plan yet again favors that sibling, they suddenly notice the unfairness in a way they haven't since childhood. It dredges up all of those emotions.
Another potential source of conflict is the new relationships your children have. They grew up. They got married. They had kids of their own. It was a time of joy and excitement.
That's fine, but you have to realize that these new relationships change things. Suddenly, their spouses and children mean far more to them than their brothers and sisters. They may be willing to fight with their siblings over your assets if they think it can help their immediate family. While they may have shrugged unequal bequests off when they were single, for example, they may fight for more money if they want to put their own children through college.
The goal is to understand why conflicts happen and what is likely in your family. You can then work to draft an estate plan to avoid these conflicts. For children already involved in estate disputes, they need to know their legal options to sort it all out.