Introduction: Please mention yourself who you are, where you are from and your family relations etc.
Academic Qualifications: mention what you have achieved academically, if there are any gaps and explain what you did in between the gaps accordingly.
IELTS or Any other English Language Test/Work Experience/Internships: If you have done any other English Language or IELTS highlight in this paragraph. Also include work experience and Internships.
Reason of choosing the course: state the interest on the course including past experience or study, benefits of course, career outcomes, comparison with other similar course etc.
Reasons of choosing the country: point out education system, technology, climate, rules regulations, international students policies, why not other destination etc. in this paragraph.
Why this university?: you can visit university web page and get reference about this and some of are in the concern governmental website. Highlight and compare fee structure, course/subjects, location, language requirements and education system and its globally recognised degrees etc.
Future career and plans/sponsors:
Visa conditions/reasons to come back home country
Conclusion
Please find some of the sample documents like SoP, Letter of Sponsorship, Property Valuation, Banking Documents etc. for applying higher education in UK.