Clear signs and arrangement of collections are important to promote a library's fiction collection. I think going along with this, if you have the collection arranged how you see best fit using the signs you think are best fit, you still need to be open and receptive to change based on the patron's needs. For example, at the IU Education Library where I work we have a sign above the reference desk that says "Ask ? Here". However, no one seemed to ever approach the reference desk to ask their questions but would go to the circulation desk instead. The circulation workers would direct them in the reference desk location or attempt to answer the question themselves, but overall there was something about the reference desk location or signage that was not working and needed a change. Fiction collections can suffer similar problems. Even using clear and simple signs and arrangement that makes sense, this still may not work for the patron. Being open to suggestions and noticing repeating problems is essential in rearrangement of your collection. Librarians become so used to their environment that it is hard to see problems patrons may have. It could be useful to have an honest friend who is not familiar with your library visit your fiction collection and see if they can easily navigate the area and take any feedback they have on ways in which it was confusing or difficult.
Book displays seem to be a very effective method of showcasing your collection. Book display areas should ideally be open and easily accessible to the patrons. When I worked at high school library I would make displays throughout the library on any available surface. The displays that were at hip level and without barriers by far circulated the quickest. However, administration also requested displays in locked glass cases. These displays were still open to circulation but the patron had to come ask me to unlock the case for them to get the book they wanted. I would put many signs around the display to make it clear that these books were available to check out, however oftentimes no one would check out books from these displays because of this extra layer of work.
Bookmarks are also a great tool for displaying information about a library's collection. I have also found them effective to use to promote upcoming library programs and events. If the bookmarks are in convenient locations such as the circulation area or even throughout the fiction section, patrons of all ages are likely to reach for them to use for the book that are about to check out. Bookmarks do take more time to make and also may be easily lost by patrons, however even if the bookmark only lasts for one book, the patron may better remember the information that was on the bookmark. Also, if they find the information handy, they are more likely to keep the bookmark around to reuse.