I know for a fact that whenever somebody makes up his mind to write an essay, it is always his desire to do a good job of the same. A person may appear careless and clueless in life, but when such an important thing as an essay comes up - be it for personal use like in a class setting or for purposes of a writing company of sorts-every one of the essayists always wants to give it his all. Unfortunately the desire to write well does not always translate in good essays being written; the chief reason why is it so are common mistakes that can and should be avoided during essay writing.
One of the commonest mistakes that could hinder the quality of ones essay is the use of apostrophes in words. Many people make basic errors when it comes to applying apostrophes in a word in the sense that there is always a confusion as regards to the application of an apostrophe in a singular word, plural word, word ending with the letter 's' and in the possessive nouns and pronouns. Another basic mistake always comes in the use of the expressions 'it's' and 'its'. The two expressions are very different - the former meaning 'it is' and the latter showing an element of possession.
Another mistake comes in the shape of spelling and semantic confusions of words and expressions that can easily be jumbled like 'there' and 'their', 'effect' and 'affect', 'who' and 'whom', 'travelled in' and 'travelled by' and so on and so forth. Such words need to be considered carefully before one can use them in an essay. The use of capitalization when not needed or forgetting to use it when needed is also a common error that needs to be avoided at all costs, just as the use quotes as sentences on their own. Quotes need to be used as part of a sentence at all times. There are so many things that can be spoken about as those to be avoided in a sentence, but I feel these are the most fundamental ones.