A route that follows 372 different footpaths and encounters 765 junctions may be an absolute nightmare to follow. Make sure the route is simple to follow, even at the expense of time. It is no use plotting a straight course across a mountain range, you will soon tire of needless walking up and down slopes. Learn to use all the information on the map and get used to the contour of the land. If your destination is on the other side of a mountain or hill and there are no obvious paths or landmarks you may well be better off going around the slope rather than up and over it.
Safety is an important factor too.
Steering clear of MOD property, shying away from industrial areas, making sure your route is not too isolated are all examples. For use in Scouting I would suggest that your route, wherever possible, never strays too far from 'help'. This may mean a town or farmhouse or maybe just a telephone. A longer route that veers slightly to stay near to 'help' will be much safer than the direct route 'across the middle of the desert'. Planning an appropriate route can take into account your circumstances.