Most parents, and their lawyers make these same mistakes when naming guardians for their children.
You should never name a couple to act as guardian when you really only want one person in the couple to raise your children. And then not saying what should happen if thos person is in the same accident as you or otherwise can't serve.
You should never name just one possible guardian. What if something happend to youyr first choice. You'll need to make sure you have a backup plan in place to guarentee the well being of your children.
Considering financial resourses when deciding who should raise your children. Your guardians do not have to be the financial decision makers for your kids.
Another common mistake is not protecting the financial resourses adequetly. A will means the court MUST get involved to distribute your money, making your kids' inheritance a matter of public record. That makes life more difficult for the people you love. You need a comprehensive plan that stays up to date throughout your life, keeps everything private, and makes it easier for your loved ones!
Make sure you exclude anyone that might challenge your gaurdianship decisions or who you know you'd never want to care for your kids.
Make sure when you name guardians that it's not only for the long term, but for the short term too, in case you're ever in an accident. What would happen in those immediate hours until the permanent gaurdians arrived. These is a big one to think about.
Naming guardians is a very important thing and a very big deal. Please don't ever take it lightly and always seek professional help if you're not sure you're covering all of your bases.