If you ever want to feel bulletproof, I recommend completing a solo cross-country trip with a seven-month-old baby. Or try it with a 19-month-old who looooooooves to walk. I've done both, and enjoyed it.
(At left: the seven-month-old, distinctly unimpressed with the Five Guys at Dulles International Airport.)
Part of the reason is because the occasions gave me an excuse to make checklists and do some advance planning. And part of the reason I enjoyed the trips was because I had planned ahead.
Here are the general steps I take to keep from losing my mind with all the logistics of flying for two.