Generally a base tune for me, begins with leaving the ride height at zero on most cars, then setting up the springs based on weight distribution. The NSX is 45/55 if memory serves, so to begin with, I'll use the slider scale on the spring rate adjustment to make the front 45 and the back 55%. Then the dampers I set relative to the springs. If the springs on the back for example, at 55% are set at 12 and the max is 17, 12/17 is roughly 7/10 so I set the bound and rebound at 7.
Generally then I'll set the ARB's at the opposite of the dampers so if the dampers are 7/10ths of max as in this case, the ARB's will be 3/10ths of max, max = 7 and therefore 2.1 for 2 after rounding.
For toe I generally start at -.05/+.05 and Camber around 2.5/2.0. Brakes generally at 6/5 to start and fairly low LSD settings like 8/12/12.
This is after running the car stock a few laps to see how it feels and get an idea of laps times. Then run it with this basic tune, and see if the times are better or worse, but mainly I'm looking for balance to begin with. If the car is too loose in the back or pushes in the front, I then tune that end of the car to fix that problem to get to balance.
Once you've achieved balance, you then play with the other settings to begin lowering lap times. Balance to me, is the number one element to going fast. Once you've achieved a good balance, you've done most of the work and after that it's mostly fine tuning for making the car feel the way you want so you are confident in it and can run consistent lap times.
Make changes 1 at a time and run the car, but don't be afraid to make dramatic changes and see what happens. If they ARB's are at 2/2 for example to start, don't be afraid to go to 5/5 and see how the car feels. If the springs are at 9.0/9.0 don't go to 9.1/9.1, go to 11/11 and see what happens. It's often easier to feel the difference between these drastic changes than with small changes. Once you know what the drastic effect is, the effect of smaller changes will be easier to feel.
Remember also, the effect of ride height settings in the game is reversed. If you want more grip on the front, you raise the front, not the rear, as in real life. This one thing alone screwed up all my tuning for the first 3 months...lol. I almost always run equal heights front and back, but as a last resort when all else fails, I use ride height differentials to stabilize the car, usually the back in MR and FR cars, and to get the front to turn in FF and 4WD cars.