(1) "One character in this novel...For 10 points each:"
This bonus leadin provides a specific clue for the first part. Whenever the bonus theme is self-evident, you should probably use this format, because it allows you to put in an extra clue and avoid superfluous language. By self-evident, I mean that the language of each bonus part is sufficient to establish the connection between the answer to that part and the text of the bonus that has already been read.
Consider this rudimentary example:
The question text does not have to strain to provide connections between each part. Players are very familiar with the "work/creator/related thing" bonus format; starting this bonus "Answer the following about a British novel, for 10 points each" would be entirely superfluous, because the text of the question fully establishes the connection between the three parts without the need for any overarching explanation.One character in this novel is in love with Lucy Manette. For 10 points each:
 Name this novel that begins "it was the best of times, it was the worst of times."
ANSWER: A Tale of Two Cities
 This British author of Oliver Twist wrote A Tale of Two Cities.
ANSWER: Charles Dickens
 At the end of A Tale of Two Cities, Sidney Carton takes the place of this Frenchman at the guillotine.
ANSWER: Charles Darnay [accept either underlined portion]
(2) "Answer the following about..., for 10 points each."
In older packets, this format of bonus predominates. Although it's great to use the leadin to give players an extra clue whenever possible, this format remains appropriate when the theme of the bonus is not self-evident.
Consider the example below:
Although it's possible to write a bonus with this theme that begins with a clue about Germinal, it would likely have to connect each part with language to the effect of "another author who was inspired by coal mining" or "another book about coal mining," which is unnecessarily wordy and strained. I prefer announcing overarching connections in the leadin, because it lets the players know that the bonus will be looking for a set of answers that are related by a theme such as "coal mining" rather than the typical format where the three answers are related more intrinsically.Answer the following about literature discussing the coal mining industry, for 10 points each.
 This Emile Zola novel, named for a month on the French Revolutionary Calendar, describes a coal miners' strike in France.
 This author's upbringing in the coal mining town of Eastwood, Nottinghamshire inspired his short story "The Odour of Chrysanthemums."
ANSWER: D.H. Lawrence
 This nonfiction work by George Orwell, which describes the working class of northern England before World War II, contains an extended discussion of coal mining.
ANSWER: The Road to Wigan Pier
This is a good space to say that, although it used to be common practice for third bonus parts to take an eyeroll-worthy sharp left turn (i.e. "Another writer who had a protagonist named Dave was Jimmy Johnson, who wrote this novel about..."; perhaps these can be called Trygve Specials, after their #1 producer), writers should try to do a better job keeping the parts of their intrinsically themed bonuses more closely related to one another. If you need a whole clause to explain the connection, it's probably better to find something that's more tightly connected (or take a step back and write a bonus that begins "name these novelists who wrote about people named Dave").
Note that you should not say "answer these questions" unless you are actually going to have players answer questions (which end with question marks). I prefer "name the following [authors who wrote about coal mining or what have you]" or "answer the following about [books discussing coal mining or whatever]" or "name these [books about coal mining or whatever]."