Quality stationery should always be used for correspondence.
Personal letters should be handwritten on white, ivory or cream paper; more modern styles may be in unusual colours.
Traditionally paper with a letterhead is used. On blank paper without a letterhead, the address is written in the top right-hand corner.
All personal correspondence should have the date written out in full, for example 1st December 2014, not 1/12/14.
The sign-off depends on the salutation. As a broad rule, if you addressed the letter to 'Dear Mr Debrett' the sign off is 'Yours sincerely'. If addressed to 'Dear Sir/Madam', then 'Yours faithfully' is correct.
For more personal correspondence, letters can begin with something informal such as 'Dear John'; sign-off such as 'With love', 'Best wishes' or 'Love from' are usual.
Envelopes should be neatly written, taking care to ensure that names are spelt correctly and that the correct forms of address are used.
The address should be centered, with each new line increasingly indented.Don't frank pieces of personal correspondence - use a postage stamp.