PAT: So I guess I should say more what I did wrong rather than what I did right for this section. My main problem was that I underestimated the PAT. I mean, it's a section about shapes, how hard could that be, right? Turns out it can actually be quite difficult. That being said, the key to this section is simply practice. Crack DAT PAT is definitely the best resource out there in my opinion. Get the 10 test version at least a month before your exam date, and just dive in. You'll most likely be terrible at first, but with enough practice it will just start to click. Ross' PAT videos are also pretty good if you want to learn the most commonly used strategies for each section. In summary, practice is key, make sure you give yourself ample time to learn how this section works, and don't be discouraged if you suck at first. I focused too much on my sciences and only gave myself 2 weeks to learn this section. Please don't do that.
QR: I've never been a strong math student, so I knew this section was going to be a struggle for me. I started by watching Chad's videos, which was a great way to reintroduce myself to topics I haven't seen since high school. I then moved on to DAT Math Destroyer (not the section in the larger destroyer book, the actual stand alone Math Destroyer book). I got like a 16 on my first practice test, but eventually worked my way up to the point where I was getting consistent 18s (about 10 practice tests in). At that point, I stopped taking practice tests, and just refreshed myself on my formulas every once in a while. I knew I wasn't gonna' break 20 on this section without spending way too much time studying for it, so I was happy with where I was at that point. Just a little caveat though, while the destroyer sciences are much harder than the real DAT, destroyer math isn't. What you're getting on those tests is about where you'll be on the real exam. At least, that's the way it worked out for me.
Bio: I once saw a phrase on this forum that I think sums up the best strategy for bio, so I'll just repeat it here. "Breadth before depth." The thing about the bio section is that it's incredibly random. You're just gonna' have to accept the fact that there will be at least one or two questions where you'll need to make an educated guess. To prepare, I personally used Cliff's AP biology followed by DATQvault. The fact that I'm a bio major also helped me out on a few questions. If you have time to take one upper level bio course before your DAT, I would definitely recommend genetics. I had quite a few genetics problems on my DAT, and I'm pretty sure I got them all because they were things I had already seen in class. You should definitely spend the most time on Bio out of your three sciences. The key is to just expose yourself to as many different topics as possible. Also, try not too get too caught up in very specific details. Most of the questions I had were pretty broad.
GC: I used essentially the same strategy for GC and OC: Chad's videos followed by destroyer. I really can't say enough about Chad's videos. They are absolutely phenomenal. When watching his videos, I treated them like an actual college lecture. I would sit at my desk, put on a video, and take notes. Once I had watched all his videos and gone over my notes, I moved on to destroyer. After I finished destroyer, I had a pretty good idea of what my weak areas were. I went back to my notes, and recopied the things I was struggling with. Using this strategy, I was able to condense the GC section down into 2 pages of notes. I studied these 2 pages to the point where I could practically recite them word for word. Then I went through destroyer one more time. I used an identical strategy for OC (except I had 10 pages of notes instead of 2).
OC: Like I said above, I used an identical strategy to GC here. I just wanna' throw one tip in here for the science section in general: keep moving. Assuming you're not some kind of robot, there will be a few questions on the science section that you're not going to know. Don't panic. Reread the question (this is especially important on bio since they tend to phrase questions in a tricky way), and try to figure it out. But, the second you feel like your spending too much time on a question, pick an answer (I'm a choose C kinda guy, but it's totally arbitrary), mark the question, and move on. Best case scenario, you're able to come back to that question once you've done everything else. Worst case scenario, you can't go back to it, but you still have a 20% shot that you chose the right one. Using this strategy, I finished the science section 45 minutes early, and was able to go over every question twice.
RC: Like I said in an earlier post, I've always been a bookworm. RC is something that just comes naturally to me. I really don't have a magical strategy that's gonna get you a great score, sorry. I just read the passages all the way through, answered what I remembered, and looked up the rest. One potentially helpful tip is that it's much more important to remember the order of the passage, rather than all the small details. That way, if you get a question on a really specific detail, you know where in logical order of the passage it fits. Jumping right to the general area of the answer obviously saves you a lot of time.