Yes, you could just be careful and get similar results but being careful takes more time. Time is money. This way you can just jam the tap in there and be on your way.
Step 1: Materials
3/4" thin wood. Thicker would be better but I was worried about making it too thick.
Hacksaw or angle grinder etc.
Step 2: Screw Metal to Wood
Blast some holes in the corners of the metal.
Line up at least one edge of the metal with the wood.
Twist down some wood screws through the corner holes.
Step 3: Drill Guide Hole
Drill near the edge or corner so you can fit this jig in close to protrusions on your work piece.
The tap will slide in here.
Step 4: Using