3D print (or otherwise sculpt) and original form
Cast a mold in silicone to permit replication thereof - I've always used Smooth-On MoldStar 30 two part silicone, it's quite forgiving and doesn't require de-gassing for most uses.
Cast duplicates with your resin/base and pigment of choice! I tried two mediums, being hot glue (an affordable but labor-intensive option resulting in highly porous final products) and clear epoxy
More details to come!