For the expedition, it's well worth the planning stages and if you can, recce the area - particularly the camp sites. Stick to those plans as best you can and make sure you camp where you say you will! Being in familiar territory will make navigation easier, and when you're tired and demoralised at the bottom of yet another hill you might at least know that the going is easy on the other side....
Will there be assessors out to observe while you're expeditioning? There was when I went(growing up in Perthshire you don't have to travel far for the hills). We were not only assessed for making it through the expedition but how well we stuck to our plans too.
Then again, if I'd had my choice I'd have taken a canoe abroad for some proper adventuring but all we had for resources was what we could beg, steal or borrow from the local Cadet force. Including the assessors!