@shahbaaz..

well dear...ur suggestions r worthy of applause but i m forced to disagree with ur some suggestions...

1:not shaving on the morning of interview can be very repulsive...if u dont shave in the morning..u r presenting brandnew car with a dust on it...i suggest to shave a night before and also in the morning n then take a heavy shower...heavy shower will heal all petty cuts n will act as a facial also...
similarly..after shave is also necessary as it smoothes ur skin after shave..it serves the same as filer does for nails...

2: knot of tie as u suggested depends on the type of collar one is using...nowadays normally frenched collar shirts r in vogue...n one doesnt use double knots with french collar...but if one is using english collar then one can use double knot but 4 bachelors single knot is alwayz prefered...

3: wearing suit even in summer is customery 4 interviews...so half shirt is dead issue...