AA.com for flights, hold, then use live help to tweak and check that I have the lowest fare. (No charge for EXP.) Then a combination of hotel sites and/or aggregators like Hotels.com and tripadvisor, which can access other aggregators. But since a lot of this is trade shows, I'll check with the show's housing bureau to see the rates they've negotiated, book one with a CC hold, then call my personal picks directly a week before the show to see if demand is light and they're willing to bargain further. Last week's IBS in Las Vegas had the bureau getting me Paris for $129, which is pretty good, but I went back to old stanbdy Circus Circus for $38 -- new west tower, top floor and walkable to the convention center.