Everyone is on step 2 before they did step one. Weight balance should be done first before you put the car on any type of scale.
There are 2 quick methods: First way is to set droop and ride height with setup wheels installed. You then find the center point on your shock towers (f/r) and then you can suspend the car with string from those points (Schumacher towers already have it marked
). Next you lift the car until the setup wheels release or touch at the same time (must move components around until they do).
Another way is a similar method, but you rule out any suspension by placing a small balancing bubble onto the top-plate and suspend the car. Then move weight around until the bubble is centered.
Only then you can truly tweak a car on scales