I am a UK passport holder living in Malaysia and am due to present a conference in Shenzhen

David, are you applying for it from Kuala Lumpur for both of you? You should apply for an F type while your GF should apply for an L type at the CVASC office in Kuala Lumpur. Both of you need to submit a valid passport, a photocopy of the passort, a fully completed application form affixed with a recently taken photo, and the original and photocopy of residence card/entry permit for Malaysia. Besides, she needs to provide round-trip tickets and hotel reservations while you need to provide an invitation letter from the hosting party of the conference.