How to write a letter for the reading and writing paper

First of all, as with all letters, we address our reader. If it is formal, we use the term 尊敬的 (zun jing de) , which is more respectful. If it is informal and you are writing to one of your relatives or friends, we use the term 亲爱的 (qing ai de), which is the equivalent of "dear".

Then you can continue with the main body. 

At the end, use the phrase 敬礼 （jing li) on the bottom right. This is the equivalent of 'Yours Sincerely'.