State your opinion as an opinion, not a fact. To write a strong paragraph, find some evidence to back up your claim.
Example:
If your claim is that airplanes are the best method of travel, find a reputable source that explains that airplanes are the fastest. Then explain how that contributes to your opinion.
You should tell them to knock before walking in of course. Make good eye contact and explain your demands, if the employer tells you no, do not give attitude.
