Hey guys, if i want to check my rig's power consumption, what best way to do it?
From a wall socket or else? If so, then how properly?

This topic might help you.

It says that you simply have to have a multimeter that you will connect between the wall and the PSU to measure amps. Then you multiply by 120 volts to get power. (P=V*I)

Good luck

Using a watt meter like Kill-A-Watt that plugs into you wall socket and your computer plugs into that.

That's if you have one...
Is it worth it to buy that only for a test of a few minutes ? If you have a multimeter and you're not afraid of being electrocuted, use it !

If you are going to measure the current rather than the safer Kill-A-Watt then use an RCD just in case.

Something like this.