Overall Bullmastiff grooming doesn't take too much work, and these big dogs' coats likewise don't require a lot of care--though their size means there's a lot of coat to maintain! The coats, while short-haired, are double-layered, so while shedding is light for most of the year it gets heavier during the spring and fall shedding seasons. Brushing will only be necessary once or twice a week (except for during shedding season, when daily brushing is best). The best brush for a Bullmastiff is either a bristle brush or a grooming glove. Some people also like to use a shedding blade a couple of times during the periods of heavy shedding.
Luckily, the brushing process isn't complicated: wet the coat with water mist from a spray bottle, then go through the coat section by section with the brush or glove, moving in the direction of hair growth.
Bathing is necessary every 2-3 months, unless the dog gets especially dirty or stinky (which, with this breed's drooling tendency, may happen more often than with other dogs!). Be sure to use canine shampoo, and rinse the shampoo from the coat completely. Not doing both these things can irritate the dog's skin.
Bullmastiff's short coats simply aren't long enough to sport any hairstyle other than natural--so haircuts aren't required at all.
And though owners can learn all the Bullmastiff grooming needs on their own, it's a good idea to take the dog to a professional groomer at least once. The groomer can give the dog a nice makeover, and provide tips on how to groom a Bullmastiff at home.
Caring for these dogs' coats will also require the use of a few Bullmastiff grooming tools: a bristle brush or grooming glove (and an optional shedding blade), along with canine shampoo, will all be useful to have.