First, I require students to study the grammar in the book (level 4 is studying perfect and perfect progressive; level 2 just finished present simple and present perfect), and I give them lots of practice and exercises. Then, I put them into groups to present their form to the class. They present the form (i.e. Subject + have/has+ been +verb-ing) and when to use it. They also provide examples to the class from the textbook, as well as from their own lives. Each group presents the lesson to the class, and the rest of the class asks questions, which the lead group must answer. I believe in the old teaching adage, "Who does the work does the learning," so I design lessons where students do most of the work. Usually this takes more work on my end in the planning and evaluation stages; however, the students are doing most of the "in-class" work, thus learning more through teaching.
I also like this strategy because it reduced teacher-talk-time dramatically. I monitor the groups by walking around, asking and answering questions, guiding them in the right direction, and giving suggestions and clarification during the presentation, but students are talking way more than I am, especially compared to traditional grammar note-taking. It also encourages them to think more analytically about the grammar, rather than passive taking it in (or in most cases, NOT taking it in).