I have found book talking to be quite challenging. What are methods and key factors in conducting a successful book talk?
That depends on your audience and your style. A lot of people like to book talk the plot of the book until they hit a certain point where they stop and then do "the if you want to know what happens then check out" so and so.
I do this in high school and the teachers who request it are trying to get a class of 9th graders to pick an outside reading book so my method concerns speed as well as making the students want the books.
Some books I directly challenge the kids by picking it up looking at it and then saying no none of you would ever read this. That then pulls calls from the kids what what is it and always one kids will want to read it.
Sometimes I offer them future rewards for reading a particular book. I sell Wuthring Heights by describing it as simply one of the great romances of all time. That sells a lot of the girls but the boys require another step. For them I tell them that when they get to college and they meet that cute girl at a party having read Wuthering Heights will put them one step closer to their goal.
I also like to go the RIYL (Recommended if you like) rout. I will book talk the Shining (simple book talk idea. All the kids still watch Friends so I talk about the episode where The Shining was hidden in the freezer because it was so scary). When I am done book talking The Shining I will say if you like the idea of being scared and then recommend Joe Hill or other horror authors.
The key is simple. Be yourself. If you never read the book admit it and explain the the audience why they might like it anyway. Establish your bonafides. I make sure the kids know I will not recommend books I do not like but starting off with a book talk of the Twilight that makes it quite clear I do not think they should read it. It makes the students laugh and establishes that I have read their books and know what they might or might not like.