Fayas – You need to think the SIM as Many MCQ's put together as one big question. The only way to prepare for the SIM is ensuring you know you concepts well and understanding them in a much deeper level.
Practice what you have as sample SIM's from your CPA review provider and also the ones AICPA has released in the past few years ( your CPA review provider should have copies on their website)
AUD is one subject that you can learn the material well enough and tackle it head one. I mean how many ways can they ask you the same concept?? So its not like REG where you get so many “surprise” or FAR that it is so vast your brain can't handle to know everything or BEC where its like playing a lottery game.
Try to understand the reasoning behind the testing or procedures etc and it will really help you in the SIM's
Lastly – I bought Gleim's SIM package for AUD and practiced all of them. For me that helped me know – do i know my concepts well and was I able to problem solve through these or not.