SQA Higher English Critical Essay: PLEASE HELP!!!

Hi there,
im going dr Jekyll and mr Hyde for my set but I don't think its critical essay option? I might be wrong tho. my school is doing my last duchess or blood brothers for critical essays, but I can assure you your school won't tell you to write the critical essay on dr j and h if it isnt an option, so ask your teachers. my advice e for critical essays in terms of structure is:
per paragraph:

you can use more of less quotes depending on the amount of analysis you have, if you have alot of analysis per quote you can probably get away with using two. also an important note, link each quote together if you can so they don't seem as if your randomly just dropping in quotes. so for example you could say 'furthermore, (author) has shown (link to question/ previously dicussed point) by using....' and then you go into your next quote.
Also obviously use an introduction and conclsuion. introduction should briefly summarise the piece you writing about in your essay and address the question and points you will make briefly. conclusion should conclude the points you've made and remeber to refer back to the question throughout and in your conclusion to show you are sticking to the question and to help yourself stay on track and not go on a tangent. also in your conclusion you can add how the points you've made add to your appreciation of the text as a whole and evaluate it.
hope this helps!