The most important thing before trying to apply the AO's to your essay is to make sure you have an in-depth understanding of what each objective looks like in your writing. In your last essay, use highlighters to colour code the frequency of each AO (this will also allow you to identify what the examiner is looking for when they mark your work themselves). From here, compare your essay with the assigned assessment objectives, e.g. perhaps you don't have enough AO3 in your writing? Emphasise this aspect in your next essay. If the issue is that you don't feel confident in AO3 then WELL DONE you have now found a revision focus. Tailoring your writing to a set of determined assessment objectives can be challenging but the best way to reach that balance is to keep a list of the objectives next to you and use it as a guide while you work. If you are pushing yourself to get a top band answer, the terminology of the objectives can also be highly technical so, again with your highlighter, pick out key words such as 'developed' and 'consistent' to remind yourself what the examiners are looking for.