I stumbled onto this way of making simple door/drawer knobs and it has become a regular thing.
There are so many different variables to making knobs this way.
Step 1: Raw Blanks
You can start with simple or more complex cube shaped blocks that are slightly oversized to your desired finished size.
I drilled a hole and glued in a 3/8" dowel and left it about 4" long.
In the picture at the beginning you saw a two layer contrast with Cocobolo and Holly.
I made a jig from a block of wood that I could clamp to my disc sander. It was fixed at just a slight angle that it shaped a slight taper to the newly rounded knob. The base of the disc sander has a line marked to where the jig is placed for when removing and replacing in between knobs.
To shape, insert the raw knob assembly into the jig and clamp to the table base. The knob end should be about 1/8" away from the disc sander.
You must exercise caution here: The disc sander rotates counter clockwise and you will need to keep a controlled grip on the end of the dowel sticking out the other side of the jig.
Turn on the disc sander while making sure the disc is clear of the knob when starting. With the sanding disc spinning, you will want to turn the knob clockwise slowly. If the jig is at a slight angle, then as you continue to rotate the knob and push it in towards center of the sanding disc, you will achieve rounding the knob.
You need to do this slowly until round.
Step 2: The Drill Press
I missed a picture here, ...however, once basically rounded on the disc sander you can move to chucking each knob in the drill press one at a time. Work your way through the grits until you have a perfect finish.
You can also add a finish at this stage before the knob is removed from the drill press chuck.
Normally I can use the knob just the way it is, although perhaps shortening the dowel segment to what might be needed, however, in this case I cut the dowel off, sanded it and then drill for the dowel on the opposite side, leaving a nice white maple inlay in the center of the knob.
I added a few other pics of the Lolipop Knob with slightly different looks.
Give it a try, I am sure you will love the results!