We took the home tutoring route and can highly recommend.
Results can definitely be improved with good exam technique.
This post was really reassuring. I am helping my son as I really don't want to go down the formal tutoring route. I am doing all of what HappyMom suggests but we do have hiccups with the "same time every week" aspect as after school activities, friends to play and tiredness gets in the way some times - we just work around it.
One extra thing that has helped is if I have the answer sheet and he shouts out the answer. It is great for speed and also helps with accuracy - he is not distracted by the "almost" answer because if what he says is not there I just say no and he has to have another go. Obviously he will have to get used to marking the sheet himself but doing it this way he gets an immense sense of achievement - he knows in his own mind that he can get the right answers and do them quickly.
I'll lt you know next year if my method works!