MD What do I have to do from now on to get into a top tier school?

I am a rising junior and I plan on applying to Med school before the start of my senior year. My gpa increased tremendously during my sophomore year. My personal statement will explain why my freshman year gpa was so low. I will talk about how I overcame my academic disadvantages (I got into a top 30 school with a 1500/2400 on my SAT; didn't have basic knowledge of algebra, trig, etc)

Age: 19
Race: African America
College: Top 30 research institution

1st semester gpa: 3.165
Intro Biology: B
Gen Chem: B+
Calculus I: Withdrew!
Writing seminar: B+

2nd semester gpa: 3.062
Ecology: B+
Physiology: B+
Gen Chem: B-
Drawing: B-
Literature: B+

Summer gpa: 4.0
Calculus I: A
Calculus II: A

Sophomore first semester gpa: 3.938
Organic Chemistry: A
Plant physiology: A
Philosophy: A
Theology: A
Psychology: A
Organic chemistry lab: B

Sophomore 2nd semester: 3.90
Organic Chemistry II: A
Bio lab: A
Theology: A
Philosophy: A
Econ: A
Orgo lab: C+

Current cumulative gpa: 3.6
Current science gpa: 3.52

I have a lot of extracurriculars and have participated in the SMDEP program (clinic experience) + many research programs. I will be volunteering at a hospital my junior year. I want to know what I have to do now to get into one of the top 20 Med schools. Any suggestions?