How would a teacher explain the difference between the Present Perfect and the Past Perfect Tense to English language students?

A teacher who follows active teaching and active learning should give examples on a chart that was per-prepared prior entering the class. The teacher then discusses students to differentiate between the meaning between past perfect and the present perfect tense by using the time line on the board. The teacher asks his students to give similar examples using sub-situational tables. This is what we call controlled practice.Then students think of other free examples orally or written sentences on charts to be shown on the class walls each group on a specific place. Then Students respond to real situations made by the teacher e.g. T-what had you done before studying yesterday?  -Several students answer varied answers.