Another tip is this
Don't correct exams yourself.
1. You will be too lenient to yourself.
2. When you read back your answers, you tend to have this unconscious understanding of what you are saying. Because Psychology is not yet at the point were we can read minds reliably, the psych examiners correcting your mid-years will not have this unconscious understanding. They only have what you write to go on.
Ideally, you would get your teacher to correct it, but if you can't, you can get some of your fellow students to correct it for you. (Kinda like tic-for-tat, you correct theirs and they correct yours).
By the way, this is useful for many of your other subject, particular those that have a major writing component (which is basically everything except maths, and perhaps some sections of physics).