General Tips For Writing a Formal Letter

• Your letter should be simple and focused; make the purpose of your letter clear.
  
• The subject is optional,but is highly recommended since the letter will not be opened by the intended recipient first. It should start with either subject: or Re:
  
• The subject (if you include one) should be left-aligned for full block format, but can be either left aligned or centered for modified block format.
• Have an margin of 1 in on all sides
• Use a std font size of 10pt or 12 pt.
• It is also appropriate to use “To Whom It May Concern” when you are making an inquiry (also known as a prospecting letter or letter of interest), but don’t have details of a contact person.
• If you are writing to someone whose name you don't know, "Dear Personnel Manager (or other job title)" and "Dear Sir or Madam" are acceptable.
• Address recipient by personal title. You can address the recipient by starting with "Dear" followed by a personal title, such as Mr. or Ms. If you have the full name of the recipient of your business letter, you can enhance the formal nature of the letter by starting with "Dear" followed by a personal salutation, such as "Dear Ms. Levatson."
• When in doubt, use Ms. If you want to use a personal title ahead of a female recipient's full name, but you are unsure of her marital status, it is always best to use the title "Ms." followed by the recipient's name instead of Miss or Mrs.
  
• Single space your letter and leave a space between each paragraph.
• Use a serif font like Times New Roman.
• Left justify your letter.
• Leave a blank line after the salutation and before the closing.
• Use the modified block layout since it looks modern and stylish.

References

1. https://www.indeed.com/career-advice/career-development/business-letter-salutation
2. https://www.lexico.com/grammar/how-to-lay-out-a-letter
3. https://www.thebalancecareers.com/sample-letter-format-2063479
4. https://www.dailywritingtips.com/how-to-format-a-us-business-letter/
5. https://www.thebalancecareers.com/business-letter-layout-example-2059703
6. https://penandthepad.com/format-cover-letter-2068849.html
7. https://www.writeawriting.com/letter/formal-letter-format-rules-guide-examples/
8. https://www.letterwritingguide.com/businessletterformat.htm
9. https://letterslibrary.com/writing-tips/structure-of-letters/  --good ref

Writing a Letter using Latex

Latex is a typesetting system which follows the WISWYM paradigm.It can be used to   typeset any kind of document such as books,reports and even letters.  

To write a letter in you have load the letter class. By default it uses the modified block layout.

Important Packages to Load:

These are the important packages to  load in my perspective, they are

• Nag 
  
• Inputenc
• fontenc
• microtype
• setspace
• datetime
• block [if you need the full block layout]
  

 The package Nag is to prevent from running obsolete or depreciated commands.  

Inputenc  is for loading unicode encodings and fontenc is for the extended character set.

 The microtype package is for character protrusion and font expansion, furthermore the adjustment of interword spacing and additional kerning, as well as hyphenatable letter spacing (tracking) and the possibility to disable all or selected ligatures.

The set space package as the name indicates sets the line spacing. The datetime packages helps modifies the date to our liking. 

Some website may say use the newlfm and isodoc packages but compare to them this package doesn't have any other options and works within the letter class makes it an ideal package for the letter layout

 code for loading the packages:

\RequirePackage[orthodox]{nag}                         \documentclass[a4paper,12pt,oneside]{letter}        \usepackage[utf8]{inputenc}                             \usepackage[T1]{fontenc}              \usepackage{microtype}                  \usepackage{setspace}                           \usepackage[nodayofweek]{datetime}

Page styles:

The letter class supports the following styles

1. Headings
2. Empty
3. First Page
4. Plain      

We  will be using the page style empty. The code to load the style is 

\pagestyle{empty}  

  Writing the letter:

We are using the empty page style,by default the letter class leaves an 1 inch space for the header and another 1.5 in for the top margin. We will be removing the header in our document. This will make sure there will be 1.5 inch margin from top,left and right.

The commands supported inside the document are 

1. \address
2. \signature
3. \name
4. \location
5. \telephone  
6. \opening
7. \closing
8. \encl
9. \cc 
   

We begin the document by \begin{document}  in the letter the address of the sender is first written.  The From address is typed within the \address command. using \\ for starting a new line. The \signature command  as the name implies will put your name in closing leaving a space for you to manually sign your letter.

     \begin{document}   

     \address{type your address}             

     \signature{your name}

We begin the letter with the \begin{letter} followed by the receipient address. Next we add the opening greeting of the letter with \opening  followed by the subject of the letter. There is no command for the  subject. The subject must be below 1pt from the  opening and should be left justified  so we use the \begin{spacing} environment were we write our  subject.

   \begin{letter}{receipient's address} 

Before the \opening run the following  commands so that there won't be  a huge space from the top. Use the following commands with caution.If you have an header file then you shouldn't use this command. 

     \makeatletter
  \def\@texttop{}
  \setlength\headheight{0\p@}
  \setlength\headsep{0\p@}
  \setlength\footskip{0\p@}
  \setlength\topmargin{20pt}
  \setlength\footnotesep{0\p@}
  \setlength{\skip\footins}{0\p@}
  \makeatother

               \opening{Dear sir/Madam}

               \begin{spacing}{1}

                 \begin{flushleft}

                    Re: Your subject

                 \end{flushleft}

               \end{spacing}

After this write your content of the letter. A business or formal letters should be a one  page document. Finish the letter with the \closing{Regards,} command. If you have  enclosures with the letter then run the \encl{\\1. xy \\2. xx} and if you have multiple receipients then you should add courtesy copy command          \cc{\\1. aa \\2.bb} 

End the document with \end{letter} and \end{document}. The signature and closing might not be adequately right justified so use the \hfill command within that command. Finally save the file and compile in pdflatex and if compiled successfully it will produce a pdf containing your letter which you can now print.