I'm not sure what you mean.
If the material is a textbook chapter, there's something I do.
First, I leaf through the chapter and look at all the biggest section headings. "History," "Geography," "Culture."
Then, I leaf through it again and read all of the section headings. "History, Pre-Columbian, Spanish rule, Independence, 20th century, Recent history, Geography, Climate, Biodiversity..."
Then, I read the first sentence of every paragraph, because typically it will be the "topic sentence" for the paragraph. "Colombian literature dates back to pre-Columbian era..." "Post-independence literature linked to Romanticism highlighted Antonio Nariño, José Fernández Madrid, Camilo Torres Tenorio and Francisco Antonio Zea..." "Between 1939 and 1940 seven books of poetry were published under the name Stone and Sky in the city of Bogotá..."
AFTER I've read the first sentence of every paragraph, then finally I start at the beginning and read all the way through to the end.