Dogs of this breed have medium-length, slightly wavy coats that aren't too difficult to manage, but overall Boykin Spaniel grooming does require some effort. Their coats shed a good bit, so many owners (particularly those living in the Deep South) shave their Boykins' coats to half their length or more to minimize shedding and to help keep the dog cool in hot weather. These dogs will need brushing at least once a week, they'll need baths about once a month, and if clipped, they'll need their coats trimmed every 6-8 weeks.
Brush your Boykin weekly, in the typical line-brushing fashion. An oval pin brush works best for this breed, and having a slicker brush and/or a medium-toothed comb (to work through stubborn tangles/mats) is a good idea as well. If you're following the brushing with a bath, use a bathtub or an outdoor kiddie pool and a garden hose. Make sure to use canine shampoo, as shampoo made for humans (or any other kind of soap, for that matter) will irritate the dog's skin and lead to infections. Lather and rinse well, towel-dry, then give the coat another quick brush-through to make it look smooth.
If you choose to clip your Boykin, a Puppy Cut (in which the coat is shaved to about two inches all over) is a good choice. Many Bokyin owners learn to clip their dogs themselves from instructional Internet videos and such--but it's a good idea to have a professional groomer give the cut at least once. The groomer can give you instructions on how to clip the dog yourself, and he or she can pass along tips on how to groom a Boykin Spaniel in general.