These dogs' medium to long, thick, waterproof double coats require frequent brushing, but not a lot else--so Welsh Springer Spaniel grooming is not too time-consuming overall. They shed moderately (and more heavily during shedding season), and their coats are prone to tangles and mats, so Welshies need brushing 4-5 times per week, if not daily. They only require baths when necessary, as bathing can remove the oils from the water-resistant coat. And though most Welshie owners don't give their dogs proper "styled" haircuts, they may need the excess feathering on their legs, chest, and belly trimmed occasionally to keep that hair from getting too unruly.
These dogs need brushing often, because an unkempt Welshie coat will become a tangled mess. To brush a Welshie you'll need both a slicker brush and a 2-in-1 comb; first wet the coat with mist from a spray bottle, then go through the coat in the typical line-brushing fashion with the slicker brush, working through tangles and mats as you go. Finish with a pass with the comb to neaten and straighten the hair.
If you're following the brushing with a bath (and always brush before bathing), either a bathtub or an outdoor kiddie pool and a garden hose will work. Use canine shampoo (and conditioner, if desired); wet the coat, apply some shampoo to the dog's back, then lather well and work downward. Make sure to run your fingers through the thick feathering on the legs and belly. Rinse thoroughly, towel-dry, then give the coat another quick comb-through to neaten it.
A Welsh Springer Spaniel's thick, luxurious coat is one of its signature features, so most owners tend to avoid cutting it. Even so, a Welshie can receive a Puppy Cut, a short clip that makes the coat low-maintenance, if you so choose. Regardless, a dog of this breed may need its thick feathering trimmed from time to time. This can be done at home with some practice, but it's a good idea to take your Welshie to a professional groomer at least once. The groomer can demonstrate how to trim the excess feathering, and provide details on how to groom a Welsh Springer Spaniel in general.