Everyone has strong opinions, so opinion essays are usually not hard to do. Executing this type of easy well demands that you understand audience well and know what arguments, and what tone, will best sway them. Look for opinion articles, one you with which agree with and one with which you disagree. Analyze both to see how even the opinion that "offends" you uses persuasive writing techniques. Write a paragraph about how the write you disagree with tried to appeal to an audience (not only those who agree with him or her, but also the undecideds).