@meso befor you start releasing the clutch you give the gas pedal a short slight touch to build up some momentum. if you start driving uphill you lean a bit more into it. immidiately you release the clutch to the point where it starts to get grip. then you give it some throttle just so that you're around 1700-1800 rpm (depends on the car). you try to keep that rpm while you release the clutch further until it is fully released.

Getting the timing correct can be a bit tricky at the beginning.

you may not need to do it this way on newer cars as they often slighly increase the rpm when then driver releases the clutch and the engine runs at idle.