There should be no tricks when it comes to learning objectives. It is important to clearly outline what you expect the students to learn and how they are going to show evidence that they have accomplished the objectives. This can be done by a variety of methods. Communicating your objectives to your students, moreover, helps to focus their thinking and motivate participation.
For the photography lesson I am planning I intend for students to explore and create a self portrait. I want students to sketch their ideas before jumping into art making, then take their photographs. I would also like for students to understand Cindy Sherman's style of art making and decipher a narrative for themselves. Finally, self reflections are important for artist to reevaluate their choices and hear about their fellow students experiences. By the end of the lesson students should have a director's sketch sheet, final photograph, Cindy Sherman worksheet, and a self reflection.