I know this is an old thread but I think I have something to share that might help someone below?
my method for reading time goes something like this:
1. Flick through the booklet, briefly glancing at each question (at this point you can sort of gauge if you're screwed or not but stay positive at this point plz)
Spend less than a minute doing this if you have <15 mins
2. Go through the booklet again from the start and read all the questions properly. Make sure you take note of words like "always", "never" "x y z is correct when..." "all are incorrect/correct except for..." etc because these can easily be misread later on when you're rushing
While you're doing this, make a quick decision in your head about which questions you can answer right away and those you don't know or need to think about. Remember the ones that you think you can answer (or just keep your fingers on the relevant pages lol)
3. Go to the MC questions and try to answer them all in your head. If you need to do calculations, think about how you're going to do it & what formulas you're going to use
Don't worry about memorising what letter the answer is -- when you read them quickly in writing time again you'll be looking for your answer so you will be able to get MC out of the way quickly
4. Once you have an answer or a planned answer for as many MC as you can, move on to short answer and start forming/planning a response in your head for as many questions as you can.
There may be questions that you have no idea how to answer but it doesn't matter -- do the exam/SAC in order of things you know rather than sequential question order, leaving what you don't know till last
5. In the last few seconds of reading time decide which question you're going to do first and keep thinking about your planned response for this. Write it down after you've written your name etc on the paper
Another thing I like to do as soon as writing starts is write down random little notes on every question (not on the writing lines just in the margins) about what I was thinking during reading time so that I don't forget what to say. Not full words just letters, symbols etc, whatever means something to you