To make a car drift better, you just need to keep praticeing , and when you feel that the car is restricting you, and don't allow you to do a higher drift angle, or if it is hard to start a drift because it does too much understeer, then you must change your settings. Make it lower and if it oes understeer, make your rear spring rate harder than your front in the spring rate, try something like Front: 7 and Rear:8 or 9. You feel it does too much oversteer, than make your rear spring rate softer like a F:7 R:6 or make your front harder. If you use a limited lsd, than you may want to lower your acceleration value lower too, like 36 or less to do more oversteer, or if it does too much oversteer, make 40 or more.
You may try the settings that are posted in this forum, but would advise you to try to do your own settings, because everyone has his style, someones like them more grippy, others don't, so do the settings that fit your style.
Try the rx-7 cars, the FD and FC, Silvias and 180 or 240 sx, and the sprinter, as they are the great cars to drift.