1. Offer To Drive Kids To Extracurricular Events
2. Bring A Dinner To Their Home - A Healthy One Is The Best
3. Ask what would be helpful to them.
4. Play catch or whatever sport or hobby that's important to one of the children
5. If you see an opportunity to help go for it, i.e. read to a child.
6. Military families have to move a lot, if you find out moving has been ordered help them pack.
This is a great article from a while ago, but still holds true.