dont manually shift the car, its a waste of time and will net you zero gain on letting the car do its thing.
here's what i always did. put the brake the the floor and revved the car up until i couldnt keep it still anymore, then let off just a hair. from there i would let off the brake and slowly ease into it and chirped the tires just a little bit. that is what you want to do. dont spin them, but make the tires yell for forgiveness.