On top of what Gagger mentioned about asking pax to guide u,
here my 2 cts worth:
When i started, I had this huge map from NTUC income showing the
expressways and main arterial roads. I studied it to hv an overview
of the singapore topography. For eg, there are several huge
obstacles that requires drivers to do big detours such as Bt Timah
Nature Reserves, Blank Spaces which are Military Installations like
Paya Lebar n Sembawang Airbase, etc.
From north to south, what are the expressways (CTE, BKE n KPE) n
main arterial roads (eg Upp Bt Timah rd/Clementi rd, Jln
Bahar/Jln Boon Lay, Upp Thomson/Thomson rd, Upp Serangoon/Serangoon
rd, etc). Likewise for east to west.
Next I tried to memorise all the HDB estates around our central
Bt Timah Nature Reserves, east (eg , Bishan, AMK etc) west (eg, Bt
Panjang, Jurong East/West,etc) north (Woodlands) n likewise for the
south.
Then I tried to visualise what HDB estates lie above/below PIE,
what lies between PIE/AYE, ECP/TPE, SLE.
After a while, there was this grid that formed in my mind which
helped me to learn my routes faster n also understand why certain
destinations require certain routes.