By their very nature, you can’t plan for unexpected delays. If you control things like the weather, you don’t need to worry about anything because you have power beyond measure and should feel beyond the financial concerns this may raise. For the rest of us mere mortals, delays are a bridge you’ll eventually have to cross.
If you want to minimize the chance that these delays implode your entire itinerary, be strategic about your travel times and make sure your layovers leave enough room for error. If a connecting flight will be leaving in under an hour in an airport you aren’t familiar with, maybe shop around for a different configuration that will give you more time to navigate. Jet lag doesn’t care about your plans and it can strike you at the exact worst moment in terms of your trip. Miss one flight and it can cause you to enter and stay in panic mode long enough to ruin your entire experience.
Most of these tips are about utilizing a little common sense and prudence during the planning stages of your travels, helping you avoid as much of the unexpected as can be, well, expected.