If you are talking about girls' boarding schools pre-test, I don't think you need to prepare as much as for London 11+ hysteria. Our prep sends predominantly to boarding schools and knows a lot about it. It sends tons of girls to Benenden, St Mary's Ascot (which I don't think pre-tests), a decent trickle to Wycombe Abbey, etc. Both at 11+ and 13+. Majority of these schools use CEM computer test, plus full day of activities. To prepare for these, there is not point doing VR/NVR in traditional style - it's a waste of time to do GL Assessment for CEM computer adaptive test!
It is very heavy on vocab (synonyms, antonyms, cloze, analogies, comprehension) but no codes at all. So expanding vocab is good preparation, doing Bond/GL papers - a waste of time. That said, on NVR, they do test matrices, so some practice is needed.
For maths, it's problems solving - so lots of word problems, etc. The point I am trying to make is that it's different kind of preparation, less like "tutoring for the test." Some schools do papers in addition to computer test so it's a good idea to do a couple, but it's mostly about suitability to boarding life and participation in school life, given a basic academic standard is there, it's not nearly as competitive as London day schools.