I'll echo what's already been said, I usually book refundable then watch for lower rates or sales before my trip. Or I'll book with points and cancel when something good for cash comes up. My only general exception to this is during Hiltons big sales like the frequent 50% off in Asia or 33% off in Middle East, Africa, Europe which are non-refundable but I also know a better deal isn't coming around. That applies to any of your preferred chains, just happens to be Hilton is mine with Marriott a distant second. I'll go SPG, Accor and Carlson after those, rarely ever even check others.