The GPS is a tool and nothing more. It will not replace proper well thought out planning. Do the planning on the charts at home. Work it all out and have a good "PLOG" ready to hand. This will of course give you an idea of the terrain, danger/restricted/CTA areas and you'll get an idea of the fuel required.
Now you blast off and in conjunction with good VFR navigating, using the navaids and the GPS you should have a nice pleasant trip.
Quite often I fly without a GPS. It certainly isn't dangerous. It's good to keep the original IR skills up to speed. The GPS just makes it easier. (Also saves the boss money in fuel)