''It's the right bits and pieces that make all the difference,'' says Anthony P. Browne as he attempts to explain the charm of a style of decorating that he terms ''English country house.'' Without the right bits and pieces, he continues , even the best of decorating jobs don't work.
The tall, self-assured Britisher has invaded America with this well-bred English look, which he projects as an interior designer and restorer and also as an entrepreneur with three shops in the Georgetown section of Washington.
What are some of these all-important bits and pieces? For Mr. Browne, they include antique birdcages, unusual small picture frames in which to show off family photographs, toss pillows fashioned of old tapestries, well-worn painted tinware, tabletop flower stands that resemble early Victorian chemistry sets, and unusual cachepots of all sizes.
They also include big lacquered shells, choice porcelain objects, and antique floral and bird prints set in hand-painted frames. To satisfy the demand for the occasional hand-painted object that is another element of the English country house style, Mr. Browne keeps a craftsman on his staff to do nothing but decorative painting on frames and other accessories and small items of furniture.
And because 17th- and 18th-century paintings of animals are currently so popular in English interiors, Mr. Browne is also introducing Americans to a bucolic assemblage of painted pigs, cows, sheep, and horses, not to mention dogs galore of every size and breed.
''Dogs sell best, by far,'' says the designer. ''We can never find enough paintings of dogs to satisfy all our clients on both sides of the Atlantic.''
The very latest decorative hits, according to Mr. Browne, are 18th-century architectural drawings, especially those aerial views of grand estates engraved by Kipp, which are ''sensational to look at, but very scarce and very expensive.''
Mr. Browne established his first shop at 1263 35th Street, NW, a few years ago after several visits from London confirmed that the atmosphere and architecture of the historic Georgetown area felt like home to him. He also correctly sensed that this cosmopolitan capital, with its high-level career mix, could offer a sympathetic market for the English country house look that is his specialty.
Much of the antique furniture shown in his shops is Regency, and he goes to England every five or six weeks to check out auctions, country-house sales, and London dealers. He is also still active in his family's half-century-old firm, which specializes in the restoration of textiles and tapestries on a worldwide basis. This business, he recalls, enabled him from boyhood to observe and learn from the interiors of many of Britain's finest homes.
He most admired the interior design work of the venerable Colefax & Fowler firm in those houses, and now tries to emulate it in his own work. ''It was this company,'' he explains, ''which was most responsible for reviving the English country house look and for putting it in good order.''
Mr. Browne now offers the entire range of Colefax & Fowler fabrics (including the ever-popular floral chintzes) and wallpapers which that firm developed to enhance and perpetuate the country house ambiance.
To define the look further, Mr. Browne says, ''It may be peculiarly British, but I think what we do in England is to mix whatever we like together and not worry too much if everything exactly goes. It may sometimes appear to be a hodgepodge, yet the British know how to commingle many different fabric patterns and objects with a certain nonchalance and flair for hominess and comfort.''
Mr. Browne is currently doing a room in the designer showhouse in Southampton , Long Island, which will benefit the Rogers Memorial Library. In October he will participate in the designer showhouse in Washington being sponsored by the Women's Association for the National Symphony Orchestra.