Like most folks, I use self-tapping drywall-type screws for attaching plywood countertop substrate to the cabinets. They go in fast and hold tight, but they also lift up a bit of the wood around the screw’s head as it goes in. As shown in the drawing below left, the bulging substrate telegraphs through the laminate surface.
Ideally, each screw should be countersunk with a bit dedicated to that purpose. But that requires a second drill, and yes, more time. The drawing shows a good compromise. I use a spinning Phillips bit to excavate a divot in the plywood before I run the screw home. The divot isn’t pretty, but it takes out enough material to keep the fibers from lifting above the plane of the plywood surface.
Terence Walker, Seattle, WA