The Scottish Terrier is a breed that is well-known the world over for his distinct coat, stout silhouette and unique appearance. As such, it's of great importance with this breed in particular to keep your Scottish Terrier well-groomed. However, the unique look that is prized in the Scottish Terrier is made possible by a similarly unique coat that can pose some challenges to those who are unfamiliar with the breed. In a sense, a Scottish Terrier actually has two coats: a short undercoat with a texture somewhat like wool, and a longer outer coat that's somewhat harsh and wiry. This is where the look in question comes from: the longer coat tends to form a "skirt" or "apron" that extends low to the ground under the Scottie, creating a ground-heavy appearance that lends to their reputation as a "big dog in a small package".
When it comes to grooming the Scottish Terrier, regular brushing at least twice a week is absolutely imperative. The wiry nature of the outer coat and the tightly curled undercoat will mat and tangle very quickly if dead hairs aren't regularly removed through brushing. In addition, at least twice or three times a year, your Scottish Terrier will require a much more extensive grooming process if he or she is to retain their natural look. This process involves what is typically called "stripping" and it can be done either by hand or with a special knife designed for the job. This process will remove old dead hairs more thoroughly than brushing and if done correctly will contribute to the proper shape for your dog. If you don't plan to show your Scottie however, it's perfectly acceptable to use clippers to groom him or her, but certainly don't just give them an all-over short cut as this will render the breed almost unrecognizable. Basically, you'll need to use short strokes, and clip the hair starting behind the ears, down along the spine, all the way to the base of the tail. Continue the same procedure down the sides of the Scottie, following the natural guideline of the breastbone and flank muscles, leaving the "skirt" hairs untouched.
At this point, it'll be necessary to do some touch-up work with a pair of scissors. Trim the hair on the back of the tail, around the anus, above the eyebrows and try to smooth out any excess tufts of hair around the head and neck that aren't a part of the Scottie's distinctive "beard" or "eyebrows".
As an aside, one important note on home grooming your Scottie: be absolutely certain to give them a good brushing before any baths, as water will greatly increase the chance of matting for untidy coats.
If you do decide to go with a professional groomer, make sure that he or she is well-versed in the kind of look a Scottie is naturally supposed to have. Too often are Scotties subjected to an unappealing all-over "buzz cut" by unknowing groomers. As always, do your homework, and with a little care, you can ensure that your Scottie will remain one of the most unique and distinctive looking pets you can have.