Summarize the piece as a whole. Omit nothing important and strive for overall coherence through appropriate transitions. Write using "summarizing language." Your reader needs to be reminded that this is not your own work. Use phrases like the article claims, the author suggests, etc.[3]
Present the material in a neutral fashion.[4] Your opinions, ideas, and interpretations should be left in your brain -- don't put them into your summary. Be conscious of choosing your words. Only include what was in the original work.[3]
Be concise. This is a summary -- it should be much shorter than the original piece. If you're working on an article, give yourself a target length of 1/4 the original article.