THEATRE / I, an actress: Paul Taylor learns to laugh and cry at Annie Griffin's masterclass

Even the greatest actors need tips on acting. Take this wise and well-meant letter from Joan Plowright to her husband, Laurence Olivier, about his legendary Othello: 'I remember you saying about Brenda de B. that she 'tries to cry' on stage, whereas in real life one tries to stop crying. I think maybe you are trying to believe Cassio's kisses have been on her lips, instead of trying to stop yourself believing.'

This sage advice popped into my mind during the 'stage tears' bit of Annie Griffin's spoof masterclass How to Act Better, though her principles on the lachrymal front could scarcely be further removed from Plowright's. She advocates taking deep breaths, squitching your eyes and thinking of something terribly sad. Oh, and glycerin. If the result is intended to suggest someone who's watching Now Voyager while making an onion quiche, then it must be accounted a great success.

Clad in a slinky black evening gown with pearl accessories, Ms Griffin talks mostly to the camera that follows her around, a big screen at the back flashing up her magnified features. She has a flirty, confidential American television manner, and her show amounts to one very thorough demonstration of 'How to Act with Tongue Permanently in Cheek'.

Ms Griffin stops at one point and tells the audience, 'Now I'm just gonna look at you; for an actor that's the hardest thing possible.' You want to shout back that there are times when an equivalent courage is required to keep your eyes on the stage. But it turns out that no contributions or questions from the floor are invited which gives the show, for all its wacky, deadpan knowingness, an incongruously safe feel.

Rather like Esther Rantzen, Ms Griffin is flanked by three tame male assistants in tuxedoes. In the lesson on 'Being Big' (that is, projecting the kind of melodramatic emotion needed for La Dame aux camelias), the trio helps her to pump up her performance by functioning first as Echoes (feeding her feelings back to her), then Resisters (forming a scrum around her so that she has to force her way through) then Focus Points (ensuring that her emotings are directed at something). Since, likeably, Ms Griffin is the kind of performer who, in old Hollywood, would be more likely to get the wisecracking brunette roles than the romantic consumptives, the above technique merely boosts the daftness factor in her performance.

Ms Griffin's declarations tend to be no-nonsense, though. How about, 'the impulse to walk comes not from the feet but from the eyes'; or her shrewd advice about not milking an exit. True, she happens to be milking an exit at the time, but the whole show lasts only 55 minutes, which makes it feel marginally shorter than, say, any death scene involving Frankie Howerd.

'How to Act Better' plays at Riverside Studios, Crisp Rd W6 (081-748 3354), to 11 Dec