When comparing and contrasting, the key is to show similarities
despite differences AND to show differences
despite similarities.
For example:
(a difference despite a similarity)
1. Grapes and oranges both contain seeds. However, although we usually eat the seeds of a grape we do not usually eat the seeds of an orange (pips)
2. Bananas and oranges are both fruits that have a skin that needs to be peeled before you can eat it. This can be done by hand for both of them. Although, whereas a banana can be peeled very quickly, an orange takes a bit more time.