There are some kinds of trips where there's no real option to book in a way that you can cancel a week before the trip. But, by and large, you can book flexibly if you're willing to pay the premium. I'm not sure it's usually worth it in the case of airline tickets given that flexible tickets are often 2x and you can usually cancel for a $250 or so fee. But hotels usually have flexible rates for a 10% to 20% upcharge. That's what I usually do anyway (it's work travel policy) and it's certainly what I'm doing over the coming months.