#1 , #2 , and #3 : Spend a bit of time reading COC, fare rules, and the like. People spend $10K on a ticket and are upset when it turns out that they can't do what they want.

#4 : Solid and comprehensive travel insurance. Unless your credit card really does provide what you need, spring for an annual policy which does more than pay for a hotel when you misconnect. Think about being stuck overseas, getting injured or sick and then not being able to travel for 30 days. Hotel bills mount.

#5 . Don't be lulled into believing that what people here call OTA's are TA's. There are real TA's who provide real service. They typically charge a fee. If you need competent and compex advice (some do), pay for it and use someone local who comes highly recommended by people you know and trust and who has an incentive to be your advocate when things go wrong. There may be cheaper tickets to be had, but as many people find, the cheapest ticket may not be the least expensive journey.