1. appearance is key
shave or beard proper trim
hair cut 2-3 days before
nails cut
teeth clean
face washed properly cleaaned on morning of interview
bright and energetic look (even if you are not)
shoes clean
better wear suit otherwise pant shirt preferably white or light color shirt with dark pant and leather belt.

documents:
take them organized in leather folder or plastic folder. you can put them sequence wise like degree from high to low,t hen experience letter etc so you can show whatever needed and dont have to search the file blindly. other tip is to buy 50rs tabs stickers in multicolor and stick them on pages of folder with reference.

interaction:
knock on door or if its open loudly ask may i come in first
enter saying loudly Assalamo Alaikum
dont sit unless told sit down
dont shake hand unless offered

interview:
tell truth as far as possible
highlight your skills.....say if I may add to the answer please and then explain
if you have specific info relevant to the post, ask the interviewr if you allow can I add something please
after its over say thank you for your valuable time
Allah Hafiz loudly