The Bust measurement is taken as a measurement around your Bust at the widest point.
Go 14 inch down from Bust and measure shirt width at that point to get Hip measurement.
The shirt length measurement is taken from the top of the shoulder, close to the mid side of your neck, following your body down to the point where you want your shirt to end.
Think of a line going from your armpit straight upwards to your shoulder. Measure between those two points and hold the tape measure straight.
Check the length of sleeve of kurta you like. From Armhole point to the end
Hem is the widest part of your shirt at the Bottom end of your shirt. Measure it horizontaly from one end to the other
The Armhole measurement is taken as a circumference measurement around your Armhole. Relax the muscle and measure at the widest part of your upper arm.