Handheld drilling with a Forstner or multi-spur bit can be a skittish operation. However, sometimes it’s necessary when a panel is just too big or cumbersome to place on the drill press table. In those cases, simply make a small guide panel at the drill press, using the desired diameter bit to drill the hole. Then clamp or screw the guide panel to your workpiece.
The guide panel doesn’t need to be much thicker than 1⁄2" or so. To allow precise targeting of a centerpoint, extend long crosshairs outward from the initial guide panel centerpoint, and then carry those lines down across the edges of the hole afterward. That way, you can align them with long crosshairs laid out on your workpiece.