Don't just read test explanations. You have more thinking to do before that.
Here's what I do BEFORE LOOKING AT ANY EXPLANATION: (I'm assuming this is an LR problem)
1) Mark the question wrong on your exam, do not write down the correct answer or try to remember the correct answer (this is why I have friends grade my pts)
2) Write out the stimulus in argumentative form (deductive, symbolic, whatever)
3) For each multiple choice answer, write out whether you think it is correct or incorrect, then fully justify your decision
3*) For example, if it is an assumption problem, write out exactly why each of the multiple choice questions are either necessary or unnecessary. Don't do any of this "Oh, this feels like the answer" crap, else you are wasting your time.
4) If during this process you change your mind about the correct answer, fine.
5) Now that I have attempted to justify (fully) my responses, I look up the correct answer
6) If I get it wrong again, I repeat the process
Then finally, do a neat little write up of the problem
1) I thought the answer was X because...
2) This is wrong because Y...
3) I will not make this mistake again because Z...
4) The other tempting (incorrect) responses were P...
5) These are wrong because Q...
6) The correct answer is R...
7) This is the best answer because S...

(Now read a test explanation) Additional insight from the explanation is that ...
I don't care if this process takes me 30 minutes. Wrestling with the incorrect problems is the most important part of any prep test. Extensively working through an incorrect problem will create an 'impression' in your brain, which will help you avoid the same mistake in future problems. Quickly reading an explanation of your wrong answers will not.
This of course is my method, people are free to agree/disagree -- but I'm positive that this has helped me get from the upper 60's to the upper 70's (178 is highest to date)
If you have any questions feel free to ask.