Deadwood Carving
[Bonsai Tonight] Samual Tan picked up deadwood carving early and recommends to beginners:
…following the grain of the wood, using a chisel and pliers to peel away strands of wood, and wearing cut-proof gloves.
The first technique uses a chisel to deepen deadwood along the trunk.
Begin by inserting the head of the [flat] chisel [edge] parallel with the grain of the wood.
After pulling the strands of wood away from the tree, use a pair scissors to cut the separated strands.
From here there are two options. The loose strand can be pulled with finger and chisel or with a pair of pliers. First the finger and chisel approach.