Start from ~200% on your dampening. If you feel like your car is too sloppy then go higher. I usually am around the 300-400% mark with my dampening.
Aim for a lack of body roll. If your cars body is rolling too much you need better anti roll bars (or need to drop it a couple of mm as this helps too).
If you feel like your car is lacking grip (sounds dumb in a drift car right? I know xD) then experiment with tyres. I usually start with sideways all round but then if the back isnt picking speed fast enough, or im losing control I swap over towards km1s or even km2s.
You do not need to have all the power in the world. Sometimes (like with my Vista) a smaller engine can do just as well (if not better) than a higher horsepower engine. Experiment. Find out what you like and what turbo goes well with it (if you even want a turbo).
Start with 0 added angle. If you find you cannot countersteer your car quick enough for the angle you want to hold through a corner then jump to +5. If you still cant then go to +10. If you still cant after this then you need to rethink your setup as something else could be hindering you.

One last tip:

If you're ever stuck in trying to tune a car for drifting... Ask for help. We as a community are here to help others (as quite a few of you have probably seen when playing MT). Some of us are more knowledgeable than others. But input from others never harms. I myself had to ask for help when trying to tune the Panther (MX5) for drifting as I couldn't make a stable tune with it. There is no harm in asking others for input if you are struggling to tune :p