Hi [first name],
We appreciate your interest in [company name].
We’d like to thank you for talking to/meeting our team and giving us the opportunity to learn about your skills and experience.
However we ended up proceeding with another candidate at this time.
We will be advertising more positions in the coming months so we hope you’ll keep us in mind and we encourage you to apply again.
We wish you the best of luck with your job search and your future career.