There is a lot of debate about essay structure, but the way I teach it (and use myself)is:
Introduction: 1) re-state the topic positively e.g. 'Solar power is better than wind power.' if the topic was 'Which is better, solar or wind power?' 2) outline your argument briefly.
Body: take each point from your outline and write about it, using the point as your topic sentence for each paragraph and then providing analysis, examples, etc.
Conclusion: re-state your position and then re-state your argument (this is very similar to the introduction but try to use different words).
This structure works particularly well in exams. Once your have a plan for your essay, which then becomes your outline in the introduction, you can just get on and write it.
The extent to use persuasive writing features such as emotive language, will depend on the subject your are writing for. English literature classes expect them far more than say psychology.
Note that a discursive essay (something that is still sometimes expected in certain circumstances) may use a different structure.