Ask yourself the three basic questions of who (does something), what (happens) and why (does it happen) about each sentence, paragraph and chapter you read. For example, in a paragraph about water melting, you must ask who (water), what (melts), why (temperature over 0 °C). Practice at home, allowing ample time to think aloud, spot the answers and note them down. This method will help you follow the storyline of a narration or break down scientific descriptions of a phenomenon into their basic elements.
Underline general meaning sentences acting as a paragraph's main idea, the basic components of a research (sample size, method) or information on a story's characters and setting. Such elements are important to understand the meaning of a text as well as to answer questions in reading comprehension tests. If you are not allowed to take notes on the text, copy its basic parts onto a blank sheet.
Use your imagination to visualize the events described on a text, an experiment's description or what the outcome of a research means. For example, a research report suggests that summer temperatures in the coastal city of Galveston, Texas, exceed 90 °F. Think of a place with sunny weather and people dressing lightly; when you encounter a question regarding Galveston's summer climate, your mind will recall the image of sun and lightly-dressed people.
Tests allow a limited amount of time to read a text, identify its main components and answer the questions. If you take too long to go through the text, you won't have adequate time to answer all of the questions; however, if you are too hasty, you risk making easy mistakes. For this reason, do practice tests, evaluating the time you need to complete each paragraph as well as to answer each question.