Here we go again. Who is to say that in this day and age dead reckoning is the "correct way"? What we are suggesting and I agree with IOS is that all ofthese tools are used in conjunction with each not isolated from each other.
Entering GPS coordinates by hand into a handheld non aviation unit is where most GPS errors occur. Buy an aviation GPS the Garrmin 196 being a good example, build the flight from the database as IOS suggests and plan the flight on the chart with pencil and ruler and a PLOG and fly them all together. Use the other equipment available to you, ADF, VOR, DME whatever the aircraft has, look at the window. ALL of the tools together maintain situational awareness.
Use the GPS as well as the map, don't just throw it aside because when you come to the point you need the information your stress levels are already high and interpreting the information won't help them! Get used to interpreting the display as part of your cockpit ROUTINE.
Add a check of the GPS batteries to your preflight check. After all you would not take off with out checking the fuel and the oil, the batteries are no different. My GPS is mains powered with battery back-up, I include a battery check for this along with my Bose headset as part of the pre-flight check.
There is nothing big or clever about doing things the hard way!
So our intrepid flyer is slightly off course leaving him stressed, he has to work out how to get back on course and avoid an airspace conflict. His stress levels are high, he is struggling to work out his 1:60 rule and the nice lady/man from XYZ zone informs him that he has just infringed controlled airspace. Now is he sat thinking how big and clever he is because he can navigate VFR using only a map and a stopwatch or perhaps thinking that 10 minutes ago would have been a great time to have addittional tools at his disposal to ensure he did not get into this situation in the first place?
It seems to me that a lot of the advice about doing it "properly" before buying a GPS comes from people who had to do it that way as nothing else was on offer and as a result think that everyone that follows them should learn the same way.
Wake up guys and gals, we live in the Nintendo age now!