The received wisdom is that it is better to lose weight slow and steady. Otherwise, your body will start to fight to keep hold of that fat. The way I understand is 4lb or 5lb a week is as fast as you ever want to go if you want to keep that weight off.
The methods are move a bit more and eat a bit less. I do this by getting involved in hobbies that get me outside and by avoiding the most sugary things.