What are the key steps for ensuring proper P-trap installation in a plumbing system?

The key steps for ensuring proper P-trap installation in a Plumbing system are: 1. Measure and cut the pipe to the correct length. 2. Attach the P-trap to the drain pipe using appropriate fittings. 3. Ensure the P-trap is level and secure. 4. Test for leaks by running water through the system. 5. Make any necessary adjustments to ensure proper drainage and prevent odors.