In general, very young children (ages four to five) can be shown how to save money. As soon as a child is given an allowance or money for birthdays, he can be encouraged to save a portion of that money.
Setting goals -- such as making a 100 on a spelling test -- can be seen in children in the mid-elementary grades. But kids this age still need help in setting realistic goals - a child's career goal might be a combination of firefighter and neurosurgeon!
Using time wisely can still be troublesome for middle- and high-school students. Again, seeing the adults in their lives lead by example can show adolescents how to develop this skill.
All children can be encouraged to develop good habits. Setting a good example and helping your grandsons develop these traits gradually will lead to their becoming proficient in them.