How do you set off a model rocket without a launch set?

To set off a model rocket without a launch set, you can use a simple electrical ignition system. Connect a pair of wires to the rocket's igniter, which can be made from a safety fuse or a small electrical match. Then, use a battery or a power source to create a circuit and ignite the igniter. Ensure you're at a safe distance and follow all safety precautions when launching.