All simple future constructions involve three parts: the subject, the verb "will" and the main verb. For example, "I will run" or "I will go." You can teach the simple future tense to students by giving them tables with three columns, and a number of subjects and verbs. In each row of each column, they put the future simple conjugation. For example, if a given row's subject is "she" and the verb is "to walk," the table would be filled out with "she" in the first column, "will" in the second column, and "walk" in the third column. Another activity involves providing students with a similar table that is filled in, but where each row has an error in at least one section. In this activity, the students have to circle the word that is wrong.
Conjugating verbs is the classic grammar activity for verbs, regardless of tense. Conjugating verbs in sentences may not be the most fun activity, but it can help students express themselves correctly. One simple strategy here is to write the conjugations for different verbs on the board, then quiz students at the end of the week. Another strategy involves providing students with sentences, where each sentence has a blank for a conjugated verb, and an unconjugated verb in brackets on the end of the sentence. The student determines the proper tense from the context in the sentence, then fills in the blank.
Not all strategies for teaching the future tense involve drills. Some involve reading exercises. Swapping in a reading passage along with your grammar drills can help students absorb the lesson. Passages for future tense will not usually be fiction passages, since fiction is generally written in the past or present tense. One strategy involves reading a passage out loud to the class that has been written primarily in the future tense, such as a financial commentary that makes predictions about what the markets will do. Another strategy involves having students read such passages themselves, and underline each example of a verb conjugated in the future tense.
The ultimate test of a student's skill with the future tense is for them to try actually writing their own passage in the future tense. One strategy here is to give students a writing prompt, and tell them to use future tense constructions for at least half of the sentences. Another strategy is to have the students take a passage written in the past or present tense, and re-write it in the future tense. All of these strategies are for after you have taught the students what the future tense is and how to conjugate common verbs in it.