Well I did attach an sop with my application. I followed this pattern. Make a nice detailed case, including each and every point that might strengthen your case. However do avoid anything that you think might be unnecessary. Cheers
• Why do you wish to study in Canada in the program for which you have been accepted?
• What is your overall educational goal?
• Why are you not pursuing a similar program in your country of residence/citizenship?
• What research have you done into studies in your country of residence/citizenship?
• How will this program enhance your employment opportunities in your country of residence/citizenship?
• What ties do you have to your country of residence/citizenship?
• If it has been more than 2 years since you have left full-time education, please provide your C.V. (resumé).
• In the case of a minor applicant, what are your reasons for studying in Canada? What is your parents’/guardians’ immigration status in their current country of residence?
• Provide details of your education history – dates when the course started and ended, the name and address of the school, the course taken, qualification/degree/certificate awarded for the course