From the papers I've seen, there isn't much of a variety of questions they can ask you so it's not that hard to anticipate the sort of thing you will be asked. Most of the questions you get just ask you how Clueless builds on Austen's framework (ie. how an knowledge of Emma contributes to your understanding of Clueless) and there will be some nastier ones that also how a knowledge of Clueless contributes to your understanding of Emma.
I don't really have a set study technique for this module... I just sort of have a bunch of things (themes, style) that Clueless has adopted from Emma and I back them up with relevant quotes/techniques. I made a table showing the parallels and differences and basically expanded on it in my essay (I got 20 in the trial). I think it's good not only to discuss how Clueless adopts and updates the themes of Emma, but also to talk about the ironic mode of both the texts, and also compare the visual irony of Clueless (eg. "I have a way normal life..." played over the computerised wardrobe shot) to Austen's satirical techniques in Emma (eg. authorial intrusion)... it shows that you've read the book properly
it's also good to bung a definition of "transformation" into your introduction and keep referring back to it in the course of your essay. Hope that helps.