yep hiking is the best way, just look for tracks, and water, they love water, but don't necessarily need it.
listen for their calls early morning. some days in the same area, you will hear nothing, other days , they are calling all over.
but remember in spring quail are mating and raising young, in summer they can and do go higher in elevation.
in the mountains, best is to go looking at the IV, and desert. chaparral is nearly impossible with out a dog.
in the desert it's a lot easier in low brush and weeds.