Remember the rules of paragraph construction. Begin with a topical sentence that lets the reader know what the content of the paragraph will refer to. Short and snappy topical sentences catch the reader's eye and provide a concise way of summarizing what is to come afterward. Be concise and avoid long sentences. Scientific writing requires clarity and succinctness.
Technical writing is very different from literary essays.
However, this does not mean that you cannot be creative. Always spell check your work with a word processor or use a dictionary. Reread your work and edit it closely before sending in the final paper. Check for incomplete sentences and for awkward constructions. Sometimes it helps to read the paper to yourself out loud.