For psychology, most of the 12 mark questions start with 'outline and evaluate...' 6 marks are given for outlining, or describing, the study or theory asked in the question. The other 6 marks are given for showing an analysis of the study/theory. You could get these marks by giving 3 evaluations. For example if it was a study you could evaluate the method used or the participant sample. An intro/conclusion isn't really needed.
For sociology, the introduction should be a brief description of what the essay will be about. You could also include any definitions that are included in the essay title, such as a definition of the nuclear family. For the main body of the essay you could write 3/4 paragraphs. Each paragraph needs to explain a point and then evaluate it. For example, if you had a question on sociological theories: in one paragraph you could describe a theory (eg. Functionalism) and what it says, etc and then evaluate it by using other theories to criticise certain aspects of it. In addition, a sentence at the end of each paragraph needs to link back to the question. The conclusion could be a brief summary of the main body of the essay, and also (if you are doing a question based on an argument for/against) if it leans more to one side of the argument than the other.
As for revision techniques, I would suggest making cue cards, so writing the topic on one side and then a brief summary of it on the other side. Making a key words glossary may also help.
Hope this helps!