I make sure all areas that will be touched by tack are brushed and as clean as they can be and any mud is scraped off. Feet are also picked before the ride.
Sorry, but if I spent an hour cleaning Aires before tacking up, I'd have one pissed off, antsy, bored-as-hell two-year-old on my hands. Our BO will actually come out and tell you to hurry up and saddle your **** horse if you take longer than 15 minutes grooming before a ride. We had a girl at our barn that would literally groom her horses for two hours before she would even think about tacking them up. Her horses were always antsy, pissed off and difficult to handle by the time she tacked them up, but she could never understand why. The one time the trainer helped her out and groomed and saddled her horse for her, she did it in 15 minutes (start of grooming to finished tacking up) and the horse was an absolute angel through the process and through the ride.
Your horses must be absolute saints to not be bored/antsy/pissy after an hour standing there waiting to be tacked up while you make sure they're squeaky clean.
:O Duffy, and my other horses, adore being groomed! The only irritation is summer with flies. They stand, put up a hind leg and doze! Two hours IS a bit extreme, I will admit, but I think nothing on a weekend of a good 40minute groom as week days are the quick ones. Saying that... I have more horse to groom than most of you