I design and fabricate all my cabinets with one thought in mind: use quality materials and superior joinery.  I use 3/4" plywood and join them using dominos and pocket screws.  For drawer construction,  I use 3/4" stock for the sides.  1/2"  thick drawer bottoms stiffen them overall, making them rock solid and sag free.

Cabinets

Anything worth doing, is worth doing well.