General Science & Ability
1- KIPS General Science & Ability Book (Both parts are good)
2- Mian Shafiques book (Science portion is okay but Maths & Ability portion is not sufficient)
3- Caravan Aptitude Tests (Only relevant topics of Mathematics and Ability)
4- Past papers both Objective and Subjective (I will advise you to solve past papers of last 4 years). Questions do repeat in science portion. In Maths portion, they are giving same kind of questions. Solve past papers and prepare similar category questions.
5- About objective, in 2017, all MCQ's were from Matric and FSC books of Biology, Chemistry and Physics. In 2018 and 2019, this was not the case. They were surely from general science portion but not from that books. Questions were general and from syllabus. Most of them were in easy to medium category according to difficulty level. 4 to 5 questions were of difficult level. You can prepare them online easily. If you prepare MCQs from books, you can find and buy one. I had not found any useful book for MCQs. Available ones had a lot of mistakes. However, some portions were done by Caravan GK book since I was preparing for PMS GK from that book.
6- Write to the point in this paper as you will get less time to solve that many parts. Make diagrams, flowcharts etc.
7- Choose questions of which you can solve maximum part. Do not fell in trap by choosing a question in which he asked asked your favourite topic but you are not well prepared for other parts of same question. If you think you can solve all questions, solve those you know the best and which has potential to present well in subjective writing as well as by diagrams or by flow charts.
8- In Mathematical portion, forget what you used to do in Mathematics at Matriculation or at other levels. You not only have to solve it in Mathematical form but you will also have to explain it in theoretical form. You can make small phrases or sentences with each step. You might have to make a diagram or flowchart in this portion as well.
9- Some overlapping theoretical portion topics were prepared from Environmental Sciences book by Imran Bashir. MCQs of same topics were also prepared from his MCQ book.

My Scores in General Science & Ability:
2019- 74
2018- 73
2017- 32

Note:
I will soon share solved Mathematical and ability portion of at least one past paper here to give you people idea.