I ended up 'tutoring' my child myself through the 11+, sucessfully I might add
, however we did at one point consider a tutor.
He came to meet us(parents) and our son and was very good, putting my son at ease, while he quietly assessed his suitablity for a Grammar education. He did not use any kind of formal test, but was very interested in his passtimes how much he enjoyed reading, his favourite subjects at school and a whole host of other topics. I am sure my son had no idea he was being assessed at all!.
He also asked us what kind of feedback we had been having from the school. He was very keen to explain the difference between being suitable for a Grammar education and being a suitable candidate to pass the 11+ but as you need one to be a part of the other this is unfortunately what needs to be practiced. I think he was trying to get us to think about the 'bigger picture' to make sure we had really thought about the best type of education for our son, and to impress that not all children who are very bright will have the skills necesary to pass the test, and I suppose vise versa.
I think this is where the arguement of not allowing children any kind of familiarisation before the tests fall down. After all what other exam would you ever enter without having done some kind of preparation?
I know I've rambled some what but hope this helps. We are Lincs by the way with VR and NVR only.
Good luck, It's very rewarding work is'nt it