Send the interviewer a follow-up email. Thank them for their time, and reiterate that you are interested in the role and look forward to hearing back from them. Don't use this as another opportunity to sell yourself. You can, however, point out anything that you forgot to mention. Keep it short and concise.
Remember, a new opportunity is calling, so be excited! It's fun!
Lastly, always remember that when you fail to plan, you plan to fail.