John, I do not think there are many here that use iron-on (if I'm wrong,I'll hear about it).
Most use spray glue. Here are the steps I use to attach a pattern.
1) Prep wood, cut, rout,sand smoooooth.
2) Use either Blue Painters Tape or Glad Press and Seal on the wood.
3) Spray glue pattern and attach to Blue Painters Tape or Glad Press and Seal
4) Overlay or top with clear packing tape.
For small projects I just spray glue back of pattern and attach to wood.
After I have finished cutting, I use lacquer thiner to remove glue and rest of pattern.