The correct answer to this open question is the following.
Paying attention to text features and visual cues is one way to get a sense of the main focus of a text.
This is so because those elements include important tips or parts that can facilitate the reader with the comprehension of the main idea. Visual cues could be graphics, symbols, and pictures that give a hint of the content of the text. Other kinds of text features can also be the title of the text and its subheadings. A powerful title and interesting subheadings can catch the attention of the readers and be meaningful enough to get a sense of the main focus of a text.