Is that any best way to measure High side mosfet drain current?
The problem with the above setup is heat dissipation will be reduced and could overheat the part.

The source current is also the drain current for a mosfet. The way this is typically done is by cutting traces and inserting a series current resistor. If you need to know the swtiching current this is likely the best solution. 

It really depends on how accurate you need the measurement to be. One way without cutting traces is to estimate the power of all the circuitry by using a benchtop supply with a current meter and then switching loads on and off to determine how much power they are using. The power of the local circuits can be estimated from the total. The current can be determined if you know the voltage of the local circuit.