You mentioned that you have come over from Forza from GT, I've not played Forza myself but from what I've seen it looks like you are drifting on glass most of the time, the road surface seems not to have any substance to it. In GT the tyres respond to the surface much more so once you run out of momentum you will start gripping again and the car will dig in. To avoid this you need to be much smoother with your power transitions, if you lift off suddenly then the car will start gripping quite viciously which will cause snap back. If you try to be more progressive with the throttle and steering inputs then the car will be much easier to deal with. Big angles are difficult to achieve at first so start off with little slides and work your way up, don't just expect it to be easy.
As far as tuning goes, reducing the rear Toe In a little helps as it makes the transition more gentle, adding a little bit of front camber can help as well because it reduces the grip (Camber seems to be broken) making the transition back to grip less violent. Not much to it apart from that really, you get used to it after a while and stop noticing so its hard to quantify. Just keep practising, start with a low power car and work your way up, concentrate on weight transfer as its hugely influential, once you've mastered that then the rest is easy.
There's a thread in the drift forum about learning how to drift that may offer you better answers so you should probably ask in there, be careful though, there's a lot of people who have a lot of opinions but very little sense so take answers with a pinch of salt and use your own experiences to sort the good answers from the bad.