After I qualified and they started throwing me out into areas in the blind I did the same thing, relied on GPS. It absolutely kills you time wise. So I started studying a map on my iPad before bed every night. It took a couple weeks of memorizing street names and what not, but it helped. Area knowledge is everything. Open google maps during your off time and familiarize yourself with every possible route you may cover.
There are ins and outs on every route that you can only learn from experience though. It will come with time.