In compare and contrast essays, there are four paragraphs. The first one contains a brief introduction about which two things you will show the similarities and the differences.
The second paragraph contains the similarities which start with the first obvious similarity… another distinct similarity… yet another important similarity… between the two things and there should be 3 or 4 similarities at least.
The third paragraph is for the differences and there should be 3 or 4 sentences at least, the same as the similarities, the first obvious difference… another important difference... etc, but the difference is in the points.
At last in the conclusion, you will show your preference and the reasons for your choice. Also it’s not necessary to prefer one thing over the other one. You can show your preference in the two things and the reasons.