My definition of navigation is:
Maintaining straight and level balanced flight along a pre-planned track.
But
how you maintain track is down to you. Either by pre-planned visual fixes, pre-planned radio navigation fixes, GPS or a combination of all 3.
Personally, for basic puddlejumping, I like a 'paper' map and line, but also a GPS. But I don't want to stare at the gucci eye-candy of moving maps etc, I just use the CDI for checking any cross-track error.
My activity cycle is thus:
L
OOkout for most of the time
Attitude - primarily S&L attitude, fairly obviously.
Instruments - Altimeter confirms correct attitude, ASI confirms correct speed, ball confirms correct balance......and the GPS CDI is the 'trackometer' which confirms that my 'track-itude' is correct!
A chum has an Auster - and a GPS! The GPS altitude is useful as whoever rebuilt his altimeter didn't do a particularly good job as it sticks like crazy, despite all the full-spec Auster vibration!