First off, take a couple weeks to relax! You deserve it! The two biggest holdups in applying are transcripts and letters of rec. To that end you want to start working on these early, make a list of all schools you will need transcripts from, most common apps have a transcript request form that links to your app so you probably can't submit it early but make sure you have all the ifno you need to request and make sure all your bills are paid etc so the school doesn't hold up your transcript.
Next, create an interfolio account and start contacting you letter writers, they can upload your recs directly to interfolio (pick the option where you do not have read access). Once uploaded to interfolio you can send them directly to the schools you are applying to, do this as soon as you submit your common application.
Other than that do your PS, make a list of all clinical and volunteer experience and other EC's so that you can just copy/past into the application. Remember to spell check everything!