for VR I would read the question first, then skim the text, then look at the options. I used to try to remember the main 'theme' for each paragraph so I knew where to look if I had to go back to check. You could always try those reading speed websites, similar to the ones for touch typing to get faster at reading as well
for QR, if you can't see an obvious method straight away, flag the question and go back at the end as theres a mixture of harder and easier ones. Make sure you use the note pad and learn the calculator short cuts. Also practice GCSE level percentages as they tend to come up a lot. Also if a question is taking too long, look at the options, eliminate the impossible ones and make a guess.
in DM, timed practice is so helpful, it will just take time. Also use the note pad and draw diagrams of you have to.
for AR, there are lots of acronyms about for different patterns - I found YouTube really helpful for this section.
in SJT, after a while you will notice patterns on the right answers. At the beginning I would always get on the right 'side' but not the right degree of appropriate/inappropriate. You tube is also really helpful for this section.
for timings, in general I would check my time at 1/4, 1/2 and 3/4 of the way through the questions making sure I had roughly the right amount of time left - only roughly because some questions will take longer than others