Notice the title and quickly page though the selection. Observe its length. See if it is divided into sections and if these have section headings. Look at any photos or drawings that accompany the text. This should give some indication of what the text is about. Then read the assignment three times, following the method below. This is actually just as fast and more effective than reading while constantly consulting the dictionary.
First reading Read the text out loud from beginning to end without stopping. Don't worry yet about words you don't understand. There will be gaps in comprehension in this first reading, but it will give you an idea of the topic, the main ideas and the overall structure. This is crucial to establish a framework for the second reading.
Second reading Now read the text more slowly, either silently or out loud, as you wish. When you come to a word or phrase you don't understand, try to figure it out without using the dictionary or any other reference work. Is it a cognate? (Does it look or sound like an English word, or a word from some other language you may know?) Could it be a new form of a Spanish word you already know? Can you tell what part of speech it is? (Is it a noun —does it name a thing— or is it an adjective —a word describing the characteristics of a person, place or thing?) This may help you guess its meaning, or at least narrow down the possible meaning. Using your sense of logic, probability or common sense, can you make a guess as to what it probably means? These techniques will allow you to figure out many of the words or phrases you did not understand on the first reading. But there will probably still be things you do not understand, so it is time for the third reading.
Third reading: Use the dictionary or reference materials to clear up any remaining doubts. If meaning is still unclear the word or phrase may be part of an idiomatic expression (for example Me costó un ojo de la cara, which literally means It cost me an eye out of my face is used in the same way as the English expression It cost me an arm and a leg.) If you find yourself looking the same word up on several different occasions, chances are you will see it again. Start a personal vocabulary list of words to learn; it will save you from looking the same word up multiple times and help you learn these frequently-used words.
Reading this way takes roughly the same time as one slow reading with the dictionary, yet results in greater comprehension, in part because you have read the work through three times instead of once.
If the text is a work of literature, also pay close attention to sound and rhythm, metaphor and imagery. In literature, how an idea is expressed is often as important as the idea itself. Poetry in particular reveals more of itself with each rereading after comprehension has been established.