The first sentence is key to every new chapter: It should reflect the genres/genre elements that you and your readers love so much, and is the promise that will entice your readers to keep reading that chapter or skip to the next.

Example: Although the structural genres of a book might be Romanct/Thriller/Adventure, the elements you might love could be romantic/comedic/coming-of-age drama. And so the first sentence/paragraph of each chapter should be romantic, comedic, reflective of a young person's coming of age experience. 

Chapter 1

Harvard snored-- But wide awake the college boy's bright blue eyes watched me like a movie. His white face glistened under moonlight while I pretended no one saw me.

"Harvard snored--" = 'snoring' provides a light tone (comedic elements)

"But wide awake the college boy's bright blue eyes watched me like a movie. His white face glistened under moonlight" = (romantic elements)

"while I pretended no one saw me." =  (Dramatic elements)