It depends on the answer asked, but make sure it actually reflects what you think the answer is to the question. i.e. it aligns with your personal viewpoint of the text. Also make sure that it does answer the question - because this is the first place you'll go wrong. Don't make it too complicated or vague, because this is something you'll have to tie everything back to in the essay. Short and sweet is my advice.
So how I look at it is if you're in exam conditions and you have an essay question/questions in front of you, consider the first thing that comes to your mind when you read the question(s). Consider whether the first thing you thought actually answers the question, and if it does, refine it, because it's probably come from your opinion of the text. Then think about whether or not its sustainable in that you can provide multiple quotes and techniques. All of this can be done in a matter of minutes once you've gotten used to doing practice essays.