The Kreg Drawer Slide Jig is going to take away all of the guess work for installing drawer slides.
It is that third hand that you wish you had when doing this job. Simply mark the carcass where the runner is to go, position the jig to the mark, put the runner on the jig, and use both hands then to drive the screws in while to jig holds the runner.
Whether you are fitting the drawer runner to the cabinet, or the drawer to the runner, this jig can do both. It can be flipped around, and clamped to the carcass so it faces out, and supporting the drawer while screws are fitted to the drawer.