All previous comments are valid and great advice. Mine would be to carry a bag of barley sugar lollies to suck on. They keep the sugar levels up and stop the pressure head aches so are more alert especially on the longer navs. You have the ten minute markers on your maps so that is when its time to do a CLEAROFF and navigate. DONT overnavigate its a waste of time. Pick a big feature to fly to that's on track and flt towards it, enjoy the view. That's as hard as it gets. It does get easier, good luck.