Tips to improve your technique:
Driving line:- This can be a little tricky to adapt to, you need to stop thinking about the fastest way through a bend and start thinking about the longest and smoothest way through a bend. You are aiming for the same basic Out-In-Out but instead of following it with the front of the car, you are following it with the rear, the front wheels are just there to stop you going past 90 degrees.
The idea is to keep as much momentum as possible, you want to be going sideways but still progressing forwards. If you are going sideways then you are going to start slowing down, drifting was originally used as a braking technique so that passes could be made later in the corner rather than in the traditional braking zone. The more angle you have, the more you slow down, the less you have, the more momentum you keep.
You want to be turning in about a car length before where you would normally and much more aggressively in order to bring the rear around. Turn in hard, feel the rear step out, get on the throttle to encourage it and start counter steering to catch the slide. Use the throttle to balance the rear, smooth inputs to make sure you don't unbalance the car, if you lift off too suddenly the load will transfer onto the front wheels and you will pirouette around them.
Once sideways the major steering is done by the rear wheels, more throttle to get more rotation, less to straighten up. The job of the front wheels is just to follow the inside of the curve via counter steering.
Techniques:- There are 3 basic techniques to master that suit different situations but these are frequently mixed together simultaneously.
Handbrake- About as simple as it gets really, turn in to the corner hard, lift off the throttle and grab a fistful of handbrake to speed up rotation. The rear wheels will lock up and lose grip making them rotate around the front axle. Suited best to tight hairpins where you need to be facing the opposite direction quickly. In order to maintain the slide and momentum you will need to get on the throttle as soon as you let go of the handbrake.
Power Over: Again very simple, more akin to poor racing technique than drifting. Enter the corner as you would normally, slowing to the apex before picking your line and powering out. The idea is to wait until weight is transferred onto the rear wheels and then give it a big boot full of throttle and breaking traction.
Feint/Scandinavian Flick: A personal favourite of mine, I'd say I use it for 90% of drifting, a very effective way of changing forward momentum into sideways motion. Enter the corner about a car width from the outside edge, lift off the throttle and turn sharply away from the corner before turning back in and getting back on the gas. This basically shifts weight aggressively from side to side meaning that the break in traction happens quickly without losing too much forward momentum. This means that you can enter a corner already quite sideways without having to sacrifice speed which maximises efficiency and score.