1: the content of the point, do not write provocative words.
2: Apply different employers and industries, to tailor your cover letter, not maintaining the status quo.
3: ask your employer to do something for the future, not what they do for you.
4: focus on specific career goals.
5: Do not say rambling lying.
6: Do not write empty words without power.
7: should not exceed one page, unless you apply for the company to ask for further information.