LU LU Cheung was 24 when she started learning ballet. ''Why so late?'' chided her teacher. ''You could have been really good.'' A detailed explanation would have left the teacher blushing with shame at his insensitivity. ''The problem,'' Cheung could have said, ''was that I was born in Indonesia and when things got sticky for us Chinese - I was about six then - my father decided we'd be safer in Guangdong. ''Living in China was tough, then we had to adjust all over again when we moved to Hong Kong in 1972, so what with one thing and another, I never did get around to learning ballet.'' She did learn something else. At first it was out of necessity, then she got hooked and did an evening course. This time there were no rebukes. ''Lu Lu ,'' said her teachers at the Hong Kong Institute of Fashion Design, ''you are really good.'' ''That's how it started,'' Cheung recalled at the Marriott Hotel after presenting her Spring/Summer collection. ''At home, I used to make my own clothes, then after I started working, I went to the Institute to learn proper dressmaking - nothing fancy, just the basics like cutting.'' Every would-be local designer should make a point of seeing Lu Lu Cheung's work. Not a pucker on that intricate bias-cut evening gown in Italian silk. Not a hint of bunching on those full, gathered skirts. Indeed practically every garment tailored to standards many in ready-to-wear prefer to ignore. The discerning fashion student would also notice something else: these clothes are distinctive. Their label, Terra Rosalis, means Earth Rose. ''One of my assistants - a Malaysian Chinese who had studied in London - came up with the name,'' Cheung confesses. '' 'Very suitable for you,' he said and I thought: yes, that's me.'' Unlike most, she hasn't had to go back to nature. From the start, Lu Lu Cheung has stuck to her natural fabrics, colours and silhouettes - an oddity in the brazen 80s and now the epitome of the ecology-conscious 90s. Subtly blended neutrals and a striking section in rust and brown are offered for day. Cheung is up-to-the-minute with her long skimming dresses, easy pantsuits and Hare Krishna-flavoured separates, yet her stamp is clear. Weekend casuals are often sheer or expose flesh - the midriff-baring cropped top is a favourite - but good taste is never abandoned. Romance has returned to eveningwear in a big way and Lu Lu Cheung is there along with the rest - without the new gaudy excesses. A slim empire-line gown in cream silk-linen featuring sheer looped fronds falling from a frothy bodice; a pale grey draped sheath with gossamer overskirt; a fairytale full-skirted gown in off-white - like the best pastry cooks, Cheung has a lightness of touch which is evident in all her confections. Since she formed her company, Rolls Group, in 1982, the Bandung-born designer has won a strong following in Japan and now also exports to Europe, the United States, China, Taiwan, Singapore and Australia. Locally, Terra Rosalis is available in Cheung's boutiques - in Central, Times Square and Vogue Alley, Causeway Bay - plus the Trade Development Council's Design Gallery at the Convention and Exhibition Centre, and she hopes to see her label taken up by amajor department store. Competitive pricing has contributed to its popularity - separates are mostly under $2,000; eveningwear around $5,500 - but its main appeal lies in that classy, understated look. Lu Lu Cheung remains as natural as her clothes. ''I'm always learning and everything I know about fashion has come from my own experience,'' says the designer who still loves to dance and calls herself a sports freak. ''Married? Only to my work. There's been no time for the other kind.''