Volunteering for top tier?

My goal is to aim for top tier come app time and I am wondering what kind of volunteering/how many hours would make me stand out. I currently volunteer at a clinic for 3 hours a week. I have a little less than 100 hours at this point and just started my sophomore year. I genuinely enjoy volunteering and and other than the clinical volunteering I have: -program where you are paired with a person with disabilities as a "buddy" -a mentorship/tutoring program with a local public school I dont... Volunteering for top tier?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums