Best way to increase horsepower on a Ford Puma?

I recently purchased a Ford Puma and I am looking to increase the horsepower. What are the best modifications I can make to achieve this? Any specific brands or methods that have been proven to work?

Adding a cold air intake and a performance exhaust system can significantly increase horsepower.

A professional tuning or remapping of the engine can also greatly improve horsepower.

Investing in high quality fuel and regularly changing the air filter can also improve horsepower.