strike and latch mortises with rounded corners
There are router jigs that clamp to the door, but they don't offer much help on the jamb. And for the jamb there are nail-on router templates that leave little holes in your finished product. Once a guy told me he does most of the job with a chisel and uses a 1/4" forstner bit on the corners. I wouldn't trust myself to get that right every time. There are also gouges of the right radius.
How do you handle this?