While you are working on your assignment you should carefully think about the punctuation you need.  This is specially the case if you a run-on-sentence lover and you are not very familiar with the use of the most basic punctuation symbols.  Also beware of the carelessly used punctuation symbol.  Tiny as these symbols might be, their effect could be worse than expected if used in the carelessly used. Not only that, the choice of wrong symbol can change the meaning of a sentence altogether.  Remember that worse than the absence of punctuation is the wrong use of punctuation itself.  For that reason, it is a good idea to learn about the basics of punctuation before you start drafting your assignment.  Once your work is completed is always a good idea to have someone go through it before you hand it in. Any written assignment should be carefully written and proofread for punctuation mistakes.

Emoticons or smileys are not considered to be punctuation symbols and are  not used in a formal piece of writing.