Others have given you brilliant tips already. I just want to share my experience. In my last attempt I had less than a month to prepare all the subjects so, I did not have time to practice any essay. I was not even aware about the kinds of essays. I had read only 3-4 essays written by a CSP. 3 out of 4 were written in cause-effect-remedy style and one was argumentative. I knew I have to make outline and after that I had to write accordingly as much as I can. I was also aware that introduction and conclusion are most important. I spent good 40-50 minutes for choosing topic, brainstorming and making a rough outline. I left around 4 pages for outline and introduction. Started writing middle paragraphs. I kept adding to my rough outline. At the end, I concluded my essay and I made sure it was crux of my entire essay. After that, I came back to outline. I wrote it neatly and it was already organized. The last thing I wrote was introduction. At that time, whole concept of my essay was crystal clear in my mind. I started with topic sentence, I had given some background, elaborated some keywords, few sentences were according to outline and after that, last sentence was my thesis statement. I tried to give clear idea and direction to my essay in the thesis statement. Here are some of the tips that will surely help you.
1- Do not waste your entire day on essay. Instead, try to write only 5 full essays on different days in defined time limit of three hours.
2- Do not worry about material. There will be more than one essays on which you can write. Just identify the one on which you can write best. Topics are either related to current affairs or from other subjects. Students do have material for essay. Worry about it less and worry more about other things.
3- No need to select different essay just write differently.
4- Carefully read the topic. Identify key points. Do justice to all.
5- Some can be written in more than one styles. So, choose carefully.
6- Write ideas according to style.
7- Organize your ideas.
8- I like to write outline and intro at last. Check if suits you. Otherwise follow the usual method. I do make rough outline with lead pencil and erase it at end after writing neat one.
9- Write according to outline. Do not write anything which is not in outline.
10- About essay length, no one really count words. In my opinion 14-18 pages including outline are enough. Length of outline should be 1.5-2.5 pages depending upon your writing speed and number of words pr line. I have really good writing and my writing speed is also good. However, I write less words per line as I write bigger words. My essay was about 20 pages long including 4 pages of outline and introduction. I will recommend you to write at least 14 pages. I have seen people passing with even less than 10 pages. They were exceptions and their essays were too good that length did not matter there.
11- Focus more on outline, intro and conclusion. They should be flawless.
12- Organize your essay well
13- Ideas should be clear and coherent
14- Discussed ideas should be relevant
15- Do not write irrelevant stuff just for the sake of filling pages
16- It all comes to understanding of topic and identifying the key points. If you have done that part well, you will not face any problem and can smoothly write you essay after organizing your ideas.
17- No need to waste time on more than 5 full essays. Write on most anticipated topics. Rest practice outlines, intros and conclusions.
18- Mind only stops when one does not clearly understand the topic. Essays are not straightforward and often have many key points. You just need to write the most important and relevant ones. For example: In argumentative essay, 12- 20 arguments are enough. If you will choose the topic to which you can do justice, it will not give you any problems to write that many points.
19- Identify your strength. If you have less ideas, make lengthy paragraphs. If you have more ideas, write shorter paragraph. Start each paragraph with topic sentence. ive at least 2 arguments for that idea in shorter paragraph and then conclude it. Increase length of paragraph by giving more arguments.
20- Read your essay at end. Correct as many mistakes as you can. At least outline, intro and conclusion should be flawless.
21- Do not write contraction and short forms in essay.
22- Write your essay in simple possible language. Focus on conveying your ideas effectively. I used layman language and ended up getting pretty good score in essay.


About controlling nerves, it is upto you really. Try to relax as much as you can. Try not to overburden yourself. Do not leave anything for last moment study. Finish everything. However you can revise outlines of most important topics on exam day. I will advice you to stop reading at least half an hour before your exam. Have tea or coffee before exam if you can even dark chocolate is effective for calming nerves. Just think you have studied enough and you only need to use your knowledge effectively.
I had bad headaches in previous attempt so, I used to take woo aspirin tablets before all examinations and 2 before sleeping as well. To calm my mind I used different methods and even dared to used them in examination like listening music, tilawat, watching an episode of any season up to 40 minutes daily.
Apart from studying, keeping yourself composed and relaxed is another battle. Date sheet of this year is hell better than previous year since compulsory papers are one on each day. Good sleep of 6-8 hours is important to prepare you for next day papers. Without that, you will be total mess.


About precis paper, this paper has more time as compared to length of questions. I remember finishing it an hour before finished time. I started with small objective type. After that, I came to comprehension and translation. Precis was last question. Leave the questions which demand creativity, skills and thinking for end. At end, you will get relaxed and will be able to solve them calmly.

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WA-TU-IZZU MANTASHA; WATU-ZILLU MANTASHA