Elements of good writting:
A subject that you now well and understand.
A cler purpose for writing.
An audience
Punctuation marks:

1.  Capitalization Aa Bb Cc
First word of every sentence
Use to, Days of te week and Months of the Year.
First letter (only) of the names of people and places.
The main word of a title, but not articles or prepositions.
2.  Period (.)
A period comes at the end of a statement.
If the sentence ends with an abreviation, dont use more than one period.
3.  Comma (,)
Use a comma to separate a series of three or more items.
Use comma before words like, like, but, or and to separate two parts of a sentence.
Use comma after an introduction word or expression, such as however, therefore and in a conclusion.
4.  Colons (:)
Use a colon to introduce a list.
Use a colon between the main title and the subtitle of a book, article or play.
5.  Quotation Marks ("")
Use quotation marks to show the exact words someone spoke or wrote.
6.  Exclamation (!¡) & Question marks (?)
When using exclamation/question marks at the end of the sentece you dont need to add a period. (.)