1. Informal letters Beginnings
In an informal letter to a friend it may be appropriate to begin by mentioning a letter which you have recently received, or by making general friendly comments.
Useful language
Many thanks for your letter …
It was lovely to hear from you.
I was glad to hear that you had a good holiday.
I hope you and the family are well.

2. Giving advice
Useful language
You asked me for advice on ….
Have you thought about ….
It might be a good idea to ….
One thing I would suggest is ….

3. Endings
It is usual to end letters which expect a reply with a sentence on a separate line. For example:
Looking forward to hearing from you / seeing you.
Hope to hear from you soon / see you soon.
Write and tell me how you are getting on.
Write soon /See you soon.

4. Closing salutation
Best wishes and Yours followed by your name on the next line are useful general endings. For close friends you can end with Love
Hope to hear from you soon
Best wishes
Gianni

5. Formal and informal letters
Beginning
It was great to hear from you.  __
I am writing with reference to your letter of 25 May.  __
Thanks for writing to me.  __

6. Congratulations
Well done! __ I would like to offer congratulations on your recent promotion. __ Please allow me to congratulate you on your recent success. __

7. Advice / suggestion
Why not try __ What about going __ It is recommended that you contact __ You could visit __ I urge you to consider the points I have made. __ If I were you I’d __

8. Linkers
Moreover, __ Then again, __ Furthermore, __ Better still, __ What’s more, __ Additionally, __

9. Endings
Do drop me a line if you have time. __ I look forward to hearing from you without delay. __ Hope to hear from you soon. __ Keep in touch. __ I hope to hear from you at your earliest convenience. __

10. A formal letter/email of complaint about “Fairplay”(fictional band) concert
Nguyen Van An
Xxxxxx
Dear Mr Wilden,
I am writing to you to complain about the concert of “Fairplay” that you organised. 
There were a series of problems about the concert. First of all, in my opinion, the ticket price was too high, and it was not worth it, provided the concert was awful.