I find the center of the frame , front point and rear point as the starting line If the car is fully assembled it's more difficult to move the car around. With just the chassis, the frame axles, engine and trans I use my roll around gantry crane to move things around. I have some RV-trailer leveling stands with the screw height, easier to level everything. a laser level and digital level. Today there is 100 G worth of tools. 55 years ago I got more done with just a grinder, drill, and old buzz box welder.