Never thought about making shawl pins. Would be some nice little projects to try.
For making just a few, hand cutting the basic forms, maybe initial sanding with a drill attachment or similar detail sander, then hand sanding the final form shouldn't be too difficult.
If producing many dozens, a few dedicated tools for the series of specific tasks would certainly be a benefit and probably called for. A dedicated work station and tool for each task. I would think the final form finishing would entail hand sanding only.
A dremel tool, a small sanding attachment for a hand drill, maybe a small wheel sander/buffer of some sort. I would need to do a few to start to get an idea of what tool would work best for each task. Maybe even fabricate your own dedicated tool for some unusual design task.
As for finish coatings, pins made of different woods would/may need different finishes, so dedicated finishing stations would be a benefit, also.
Make a few simple forms, by hand, and decide what tools might make the hand tasks go faster or do a better job.
Would some sort of small vise be needed, also..... maybe one whose jaws are padded or leather lined, so as not to mar the delicate work.