AOA
there has been a long debate whether IH is a better optional than PAk history. in my opinion its better if you r interested n know a little about it-atleat a general idea but if you dont have a clue then pk is definitely better than IH cuz we are much familiar to it.
i took IH n my tips for the subjects are as follows.:
preparation:

• use 2 or 3 books not more.
• donot make detailed notes rather outlines, headlines under a topic.
• make timelines and flow charts
• read the books-in urdu or eng- according to your understanding , as a bed time story book.
• be very analytical n take critical notes where possible, however, keep the tone softer and positive.
• discuss the events with some friends or with your parents as much as possible. take their comments as well.
• for English, Bernard Lewis’s book is commendable especially the quotes and stanzas in the beginning of the chapter have a literary taste, which is the food for thought and for the examiner too- makes him happy.
  for urdue ameer ali is recommended or zahabi's islamic history. rest you can find books in the subject guide in this forum. pick up the book which you feel comfortable with.

paper:
in my case, i had avery short time thus i couldnt concentrate on the scholarly quotes rather i produced my own quotes in the paper, in the beginning of every question.
so my observation is tht the examiner will like the originality.but one should go for the quotes in the beginning of every question if possible.

• keep the intro short but give the idea in you mind.
• use headings where needed .you can also use bullets to answer in points.
• draw maps, may it be rough, but give the examiner idea about your awareness of the subject.
• quote ayats or ahadith if you know any,with relevance to the topic.
• quote from arabic references if you know any
• end the question with a literary sentences like"and thus was the empire lost in the ashes of time but the grandeur echoes in qurtaba "etc
• give conclusion in 2 or 3 lines.

Most importantly , in case you dont know all the questions required, dont panic just “be a passionate Muslim who can justify with all means-factual n logical-the supremacy of Islamic civilization over all others”