我一般写通知这么写的
Dear students/schoolmates
As you all know that the school has different clubs set up for your benefit. The English Club plays a very important role.
Nowadays, english has become an important language widely use by people all over the world. Being able to speak english not only enables you to find jobs easily locally, but also lets you venture abroad to other countries.
The Students' Council hereby encourages you, my fellow schoolmates, to join the English Club for benefit of your own good!
We look forward to seeing you grow into a better person with fruitful knowlegde, together with the English Club.
Sincerely
The Students' Council
NOTICEAll
the students of our school,there will be an English composition match next month.Welcome all to join us.
We will have a meeting to tell you something about the match in detail next Monday.Students Union