Dear Khan
I opted my pushto as optional paper in 2007 and I got 84 marks. I am setting in 2009 css exams.
My method is very simple.
If you want to achieve high marks in pushto you will have to attemp translation from english into pushto and pushto into english. you will have to work on english proverbs and will find its english equalants.
Next you will study :
Khushal Baba
Rehman Baba
Hamza Baba
I am sure if you work on these topics 90 marks is sure