Last year I flew over 100,000 miles, but I did a lot of overseas travel last year, flying to Korea and Japan four times. I won't do quite as much this year. I only buy one-way tickets, and buy tickets that allow me to make changes easily. They cost more, but give me more options in case I want to change a flight here and there. To me, that's worth the extra money.
Rental cars can be a problem sometimes too.
Because I'm under 25, many companies charge double in some markets, or won't even allow me to rent a car, believe it or not. I use Budget, where the LPGA has a corporate rate. For me, a luggage problem can be serious, if it means not having golf clubs to use. If the clubs don't show up with the rest of my luggage, they show up a few hours later. And I haven't had a problem with damaged clubs either, as some players have.