Once you've thanked your interviewer and left the building, find a quiet place to evaluate the interview.
Give yourself credit for what went well and think about ways to correct any slip ups. Doing this while it’s fresh in your mind will help you improve for the future.
Follow up with the employer and thank them for the opportunity and remind them why you are a good fit for the position.
Send a thank-you note to your interviewer even if you didn't get the job. You can ask—politely—for feedback so you’ll know what to improve.