Is the main purpose of your title design to organize the chapters of the book in a simplistic way, so that the reader can understand the flow more easily? If so, using a text-only chapter heading of an attractive font style will work. Proper spacing of letters could also make your text-only title look great. However, if the main purpose is to provide readers with a beautiful, visually appealing chapter heading, it is important to incorporate graphics, images, and artwork that has a lasting impression on readers. When dividing the different sections or chapters of your book, allocate which chapters will have text-only titles and which will include graphics. This will make things easier and save time. You can be as modern or simplistic as you like. However, you should also focus on ensuring that the heading design does not distract from the remaining text on the page. When creating beautiful chapter headings, be sure to use consistent formatting throughout the book by ensuring your use a similar theme for each chapter heading.