I found out the best way to improve my VFR navigation was - NECESSITY!
A few years ago, after I had got used to flying a twin, with a full set of airways navaids, & every bolt-on electronic gizmo, I decided to do a tail-dragger + basic aerobatics course.
This was in an aged Citabria. I fell in love with that aircraft, but was in basic! Only navaid was a wet magnetic compass & its only electrical item was one radio.
After my first few solo circuits, the instructor sent me off on solo cross-countries. As it was much easier to land the Citabria on grass, rather than tarmac, I headed off to various fields that I had not been to before. That's when I realised that I had to get back to the very basic navigation, that we should all have mastered. That is AFTER I got lost trying to find a small grass airfield, amongst all the other grass fields.
What it did teach me was the real value of reading & memorising the ground, & relating features to each other, as well as to the chart. The nearest I can think of is the sport of orienteering. The experience stood me in good stead, as I seem to have memorised large chunks of the South-East of the UK, from the air.
So, taking away all the navaids was what worked for me
