Pretty timely, I just spent yesterday mapping out our driving routes for a trip to Ireland and Scotland next month. This is one time where I wish I had a GPS rather than relying on my smart phone, but in Ireland we are getting a mobile hot spot so we might be able to use Google Maps after all. It doesn't look available in Scotland. Renting a GPS is as expensive as the car so I'm passing on that.
My plan is:
1. Save the turn by turn directions from Google Maps
2. Sketch out a map on paper
3. Use a paper map (though it's tough to read in detail and doesn't have many backroads)
4. Verify at least the less obvious turns with street view so I can see what the landmarks at the turns look like and note them. Some have good signs, and some might be "where that cow is standing".
5. The night before I will cache google maps on my phone using the "OK maps" trick.
This should work great as long as I stay on course. The problem will be if I miss a turn. First, I need to realize I missed a turn, and second, figure out how to correct it. I've just decided not to miss any turns. My son will be navigating. He's good at that, plus he's going to stay alert and make sure I'm driving in the right (wait, no, left) lane.
I noticed one out of the way place we're going in Ireland that google maps keeps giving me different directions. In one place it just says "turn right". No name or number, because it seems like there isn't one. I rerouted to a very slightly longer route that mostly follows the same road. There were also a couple places in Scotland where it had me taking a lot of back roads instead of just taking a few more minutes on main roads. I know there's some charm in seeing those spots, but there's not so much charm in getting lost or having a local getting mad being stuck behind me as I drive slowly looking for a turn that's miles (oops, kilometres) away.