Place the bench on the inside of the power rack with the safety pins set about a foot or so off the ground. The plates should hover just a few inches off the floor.
Those extra few inches are small enough that it still allows for a full range of motion, but it really makes a world of difference in terms of ease of getting in and out of position. It also makes it exponentially less annoying to load and unload the plates.
The pins also help serve as a depth gauge to ensure you come down far enough on each rep – similar to how you might use a box as a depth gauge for squats – and encourage you to control the eccentric portion of the rep to avoid slamming the bar off the pins.