Now that most, if not all of your applications are in, it's time to wait....and take action. Some things you could be doing:
Show some interest!
Continue (or start) visiting campuses. Some colleges do keep track. Be sure to sign-up in advance on their website and check-in when you arrive. If you can't make it, be sure to let them know.
Keep the 'Senioritis' away. Continue to study hard and keep your grades up. Most colleges look at second semester grades.
Check your email daily for college requests. Colleges may need paperwork not yet received.
In February, send colleges any updates from your schedule like a new class, or a project you are working on or finished and any new activities you may have participated in. Only send if they will add something to your application.
Interview with alumni if available. This can make the difference in an acceptance.
Fill out the FAFSA and CSS Profile (if required). Check the colleges websites for deadlines.