first and foremost pray that you will drive smoothly, eased the pressure on you and pray that the police that will assign to you will be kindhearted hahaha,,greet in a polite manner the police officer (preferably in arabic As-salamu alaykum) i dont know but maybe it lessen their bad mood just in case that some of the previous students drive terribly, if you need to talk to the officer let say you didn't clearly heard or understand their instruction be sure that your eyes still focus on the road and not in the face of him, if he told you at the middle of the road to"STOP" do not stop instantly instead check your mirror rear and side to clear your path then park your car in place where allowed to park (do not park at all driveway in front of house, bus stop, access, pedxing,,,,) then the routine of parking and say "shukran" with the smile...(though dont smile if the officer get rid of your driving skill maybe a lil bit smile and say sorry)...and pray again that your test will be fine and claim that your already passed...(although dont expect too much)...