Every essay is woven around a particular topic. Therefore, finding a topic to write on is the first thing you need to do. The principles of good writing are the same and must be followed at all stages of composition. Every essay begins with a sentence. It just happens to have a large number of sentences in it. Make each sentence grammatically and structurally correct and you have won half the battle.
Use different sentence patterns in your essay. Variety is essential to retain the reader’s interest. If you write too many sentences of the same pattern, your writing may sound dull and monotonous and the reader may lose interest. To avoid this, use all kinds of sentences in your essay. There should be long and short sentences, simple and complex, straight forward and inverted. Note that a good knowledge of the different techniques of sentence synthesis is essential to add variety and sophistication to your writing.
Variety is necessary; however, it must not be overdone. The idea is to make your essay interesting to read. This is possible only by having a simple and direct approach.
Linking words are essential to achieve the effect of unbroken continuity of thought. Most linking words are conjunctions. When used correctly, words like hence, so, therefore, but, or, then etc will connect the sentences up and make the paragraph a well-knit whole.
If ideas have to be contrasted, you can use expressions like on the other hand, on the contrary, however, nevertheless, yet and still. There are also several discourse markers that usually go at the beginning of a clause.