Always remember that you cannot get every question right. So the best bet would be to learn more about your weak or strong topics say Bold face in CR, combinatorics in Quant and make an educated guess on those questions. Once you face the question from your weak topics, if you are running short of time, you can readily skip it or if you have enough time you may read the question and think about for few secs to decide whether you can get it right or not - you can do this under 1 min. Again its your call to attempt or make an educated guess. Employ a timing strategy to help you decide on that. This is the one I follow
# V Q
0 75 75
5 66 65
10 57 55
15 48 45
20 39 35
25 30 25
30 21 15
35 12 5
So for every 5 questions, you check the time to ensure you are on track. Any delay more than 2 mins either +/- you are taking too much time for a question or you are being too fast (here you make careless mistakes). There are some other timing strategies - timing-strategies-on-the-gmat-80176.html - people follow. But I stuck with this one. Apply this in one or two practice tests.
As for the CR bible approaches - I earlier used to go through to get a better understanding of the question types, but the approaches mentioned to categorize the wrong answers simply don't work for me except for very few ones like extreme answer choices or opposite answer choices. I found that I was spending more time on trying to figure out to which category can this wrong answer choice be allotted instead of reasoning it or understanding the argument/options. While it works for many people, I couldn't get used to it. Some generic techniques work such as negation, causal reasoning etc. A rule based approach to CR doesn't work for me. I read the question stem first, try to understand the argument and come up with a prephrasing and it works out pretty well.
Taking notes is a good option to keep you focused. It is possible to take notes and answer the questions provided you don't spend too much time on taking notes. Notes should be very short, it is of no use once you finish that question. At the end, if you look at the notes, you shouldn't be able to relate to anything or understand them - it should be that short. Your speed will improve with practice. I was initially slow but eventually the speed increased. If you are not much interested in taking notes. Use the last 5 columns for each option and strike out every wrong answer, circle the doubtful ones and tick the right ones or leave it blank. At the end you should have 5 columns 41 rows with strikes/circles/tick marks. I follow that as well. You can do it for every question if not at least for the difficult ones, even that would help you keep focused. These are completely my suggestions and what I have learned from them. Everyone works in his/her own way. So check out other people's strategies and choose the one which gives you maximum accuracy and speed.
KUDOS - if my post has helped you.