Dear [收信人姓名],
[开头问候语]
I am writing to [目的或原因]，and I hope this letter finds you well. [万能句式 1：自我介绍 + 写信目的]
Firstly, I would like to [主题 1]，which is [具体内容 1]. Then，I would like to [主题 2]，which is [具体内容 2]. Finally，I would like to [主题 3]，which is [具体内容 3]. [万能句式 2：段落主题句]
As for [主题 1]，[具体内容 1]．[举例或解释 1]．[结论或感受 1]．[万能句式 3：主题 1 的总结]
In terms of [主题 2]，[具体内容 2]．[举例或解释 2]．[结论或感受 2]．[万能句式 4：主题 2 的总结]
Upon reflection，I believe that [主题 3] is [观点或评价]．[举例或解释 3]．[结论或感受 3]．[万能句式 5：主题 3 的总结]
In conclusion，it is important for us to [主题 1、2、3 的总结]，and I hope that this letter has given you some insight into [主题 1、2、3]．[万能句式 6：结尾总结]
Thank you for your time and attention, and I look forward to hearing from you soon．
Sincerely，
[你的名字]