Sometimes a drill press is nearly indispensable. Or at least a sturdy stand for your regular hand held drill. For example when you want straight holes of a certain depth, particularly when you need stepped holes for tuners.
But I really prefer my cordless drill, it's so easy and I like to think I have a good enough eye to drill straight and perpendicular to a surface. The awkward bit is then the depth stop. It's possibe to buy depth stops for smaller diameter drill bits, but these holes were already 8 mm right through the headstock and needed counterboring from the back to 10 mm halfway through. And when enlarging a hole a drill bit grabs and goes down fast and forcefully.
So I made an instant depth stop from a round piece of scrap. I set the drill bit to 9 mm proud of the end and it worked perfectly.
(The hole wasn't centered at the exit end though, I would have done better using the drill press. Wait a minute...)