Compare by criterion
A weak comparison writes everything about A, then everything about B. A stronger one picks criteria — cost, evidence, ethics, outcome — and discusses both subjects under each criterion.
Thesis first
The introduction should say what the comparison shows, not only that two things will be compared. “This essay will compare X and Y” is a topic, not a thesis.
Conclusion
State which differences matter for the question. Do not repeat both summaries.
Structure help: university essay structure. Then check the draft.