Writing persuasive essays can be both fun and challenging for students. I usually begin my persuasive essay unit by having students brainstorm ways they are persuaded. This almost always leads to advertising. I usually select half a dozen or so current commercials that encourage students to think creatively when it comes to persuasion and have them ready to show in class. [Youtube is a great source for finding commercials.]
We discuss the many persuasive techniques in advertising: name-calling, bandwagon, and testimonial to name a few, but I encourage students to focus on loaded words. Loaded words are terms such as love, peace, cheat, war, luxury, paradise, beautiful, economical, etc. that encourage strong emotions.
For practice using loaded words, I have students create a comic strip similar to the ones found in the Sunday newspaper. The comic strip may be on any topic as long as it is full of loaded words. Here is a student example:
Students have a great time creating the comic strips, and I have found their persuasive essays are rich in descriptive words after the additional practice.
If you are interested in detailed lesson plans on writing persuasive essays, you may wish to take a look at these two products on Teachers Pay Teachers.