If you have any college, trade school or military plans for after your Mission, it is imperative that you apply for the regular deadlines.
Once students' turn 18, FERPA laws prevent parents from requesting transcripts on their students' behalf. Make sure that all college applications are completed and transcripts are requested by the student before they leave for their mission.
Make sure that you also apply to all scholarships that you are eligible for while still a Senior in High School. Your scholarships will be deferred like your enrollment.