Focus: Your CV should be carefully and clearly laid out not too cramped but not with large empty spaces either. Use bold and italic typefaces for headings and important information.
Be concise: a CV is an appetiser and should not give the reader indigestion. Don’t feel that you have to list every exam you have ever taken, or every activity you have ever been involved in consider which are the most relevant and/or impressive. The best CVs tend to be fairly economical with words, selecting the most important information and leaving a little something for the interview. Good business communications tend to be short and to the point, focusing on key facts and your CV should to some extent emulate this. The longer and denser your CV is, the harder it is for an employer to comprehend your achievements.