Before answering that question, a teacher needs to be aware of the stages of literacy at which the students in the class are currently functioning. The best strategies to be used are those that most closely fit the needs of the students; the same approaches will not work for all the students at the same time because the students will have different needs and varying learning styles.
In a class filled with pre-literate youngsters, strategies will focus on helping children to recognize sounds associated with specific letters, activities to combine those sounds into words, and other very basic activities. Students beginning to read independently may need help in learning to use the context of a sentence in combination with phonetic knowledge to decode an unknown word in a sentence. Students further along in the process may benefit from practice with strategies designed to help with interpreting implied meanings or decoding meanings communicated through devices such as similes or metaphors.
Without basing the strategies on the developmental needs of specific students, the chances of increasing literacy are greatly hampered.