At the first moment i used to tune my cars for the slowest handling, but with larger oversters and angle controls. Stiffer springs, lower dampers, ridiculously low anti-roll, things like that. Then i realized that 99,9% (im not judging, its a fact) prefer to keep their cars faster, but holding smaller angles. Not because they dont like high angles, but because they feel the need for keep the pace with their mates. Everyone goes faster, so everyone needs to go even faster, and so on...
After then, and specialy after start to train using the chase cam (a.k.a. 3rd person view) i started to re-work all my cars to bring a better grip feel of the car and less "floating hovercraft". Im more happy now, specialy for that banked situations where the car used to graple the inside of the corner and overspins.
Hehehehe... i guess i didn´t answered the question. By standard i always tried to max the engine performance and then work on the handling based on this performance. Now im more on a half term, hardly i tune my cars above 550hp, but also i accept the fact that CH is not slick at all, then i try to get the biggest grip from the tires as possible, but never sacrificing the drifting extension.
Finaly, as i use too many diferent cars, i try to bring all them to a default handling feel and torque respoonse feel, so i have less time to adapt myself.