How to write.....

A Formal Letter

Yth. Bapak/Ibu (insert last name) Yth. means yang terhormat which means "who is respected"
(Title)
(Address)

(Date)

Then start the letter with "Dengan hormat" which means "Dear/With respect".... then write the body, and sign off with "Hormat saya" (yours sincerely), (insert name here).
Some closing lines are:
* Atas perhatian dan bantuan Bapak/Ibu, saya ucapkan terima kasih - for your attention and assitance bapak/ibu, i express my thanks.
* sambil menunggu kabar bapak/ibu, saya ucapkan banyak terima kasih - while waiting for your reply, i express many thanks.

An Informal Letter

When beginning a letter to a friend you can say:
(Insert name here) yang baik which means To Dear (name)
But if you know the person really well you put a personality descriptor such as:
Mary yang lucu - to Mary who is funny
Sue yang cantik - to Sue who is pretty

To end the letter you can say:
That's all for now - Sekian dulu OR Sampai di sini dulu
Regards from - Salam dari
Warm regards - Salam hangat