USING masks and mime, UK company Trestle will present a highly original drama experience for theatre-lovers this week. One of Britain's leading touring companies, Trestle is renowned for its blend of comedy, surprise and pathos. Each new show tackles new techniques, skills and issues of public concern. Add to this the unique masks that have become the company's hallmark for quality theatre. The company will stage an amusing trilogy on growing up, performed in a blend of full masks and mime that is inventive, lively and witty. The three pieces are ''Creche'', ''School Rules'' and ''Hanging Around''. The first performance will be on Friday at the Sha Tin Town Hall, and the show moves to Tuen Mun and Tsuen Wan on Saturday and Sunday, respectively. For bookings, call 694-2536 (Sha Tin), 414-0144 (Tsuen Wan), and 452-7328 (Tuen Mun). Trestle's current trip covers Australia, New Zealand, the Philippines, Japan, Singapore and China.