But my plans are usually loose, some one mentioned removing the GPS, I do the opposite, the GPS has found some fantastic little roads for me, I don't generally plot a specific route but put points of interest, or use it to get to that road I found on Google maps.
By spending lots of times with maps the GPS and Google Maps, I have found fantastic roads in NC and Smokey's, small, twisty stuff that makes the GAP look like an interstate, and I have shown locals roads they didn't know existed, they can't figure out how a Yankee from NY, can come down and show then great roads they never found, even though they ride most weekends in the area.
Also found a road in the Alps this year, that has to be the most beautiful place in all the Alps, so obscure that it didn't even show up on the GPS, and most maps of the region!!!
Here is what some research can find you, a 30km dirt road with views like this the entire ride! Could I have stumbled across it, of course, but it wasn't very likely that I would.