I got full marks in all AS modules and stick to a fairly boring (for the examiner to read) structure in terms of answering questions.
Short questions tend to be a couple of sentences maximum, "define this term" etc, and tend to define a term and place it in context (eg The term "operationalise" refers to the process by which a sociological concept is measured, valid and reliable. Sociologists operationalise concepts, such as "sexual deviance", "mental health" or "failure", to ensure that the terms are valid and understood by everyone).
For "assess" questions I generally outline the theory/study, give two strengths and two weaknesses, and try to include at least one example or study for each side.
For longer essay type questions I always do an introduction, which only has to be a few sentences (just shows the examiner you understand the question you are being asked, and know the argument you are going to make), and finish with a conclusion, just reaffirming what you've said and making a final judgement (although this final judgement can be, "X is the most important factor it would appear, although Y and Z also raise valid points which must be taken in to consideration, despite being less valid in the context of discussing power in Britain today").
My paragraphs always follow the P.E.E.L rule. Each paragraph starts with a POINT(P) - a simple statement/leg of your argument. This is followed by EVIDENCE(E) - using a quote, study or real life example to support the point you have just made. Followed by EXPLANATION (E) which extends to discussing the evidence and why it supports the point in slightly more detail and ensures the examiner knows that you know your stuff. End paragraph with LINK (L) - either link to the next paragraph (by suggesting that there are more strengths, or opposing views etc) OR LINK back to the essay question - making sure that the paragraph you have just written is answering the question (v.important) - I often paraphrase the question if I can't think of anything to say, to make it look as though I am very certain in what I'm writing. That's basically it - P.E.E.L.
With the longer essays which require you to discuss more than one perspective or study, devote at least two paragraphs to each. One paragraph will outline the theory and give evidence to support it, the second will provide a criticism to that theory, and must also be supported with figures/evidence/examples. As long as you provide a balanced argument throughout, showing that you have taken other points of view than your own in to consideration. You can link the criticisms/support with other theories too - eg The Marxist view is not supported by Blah Blah, a functionalist, who argues that differences in society are important and are necessary for society to run efficiently.
Just get a simple structure in your mind for all of the questions - all a) questions require you to outline or define a term, all b) questions will ask for differences and similarities etc etc. Once you've remembered the pattern, apply it to every answer and make sure you revise enough theories/studies for evidence, and it's not difficult.