A coping saw to cut out the basic contour.
Then I use one of the Round Surform style files for contours like that and shaping the area down.
They are about 1/2" in dia,,maybe 5/8" ?. When sarp, they cut nice. I like to pull them towards me instead of pushing them.
Handle and care for them like any other cutting tool and don't let the cutting edges clank against other tools and get dull.
You have to get the wood locked into a vise so it doesn't vibrate, that goes for any file or chisel work.
Sometimes the grain will fight you going in one direction or another. Just change direction(s) and file away down to your basic shape.
It's a rough-out tool anyway.
Then I go with a finer cut rasp and files.