Hi FakerFanboy!
I’m a first-year student at Macalester. I’m not sure how reliable everything I’m about to say is, since the admissions process is still somewhat of a mystery to me, but I’ll do my best. 
You can look at the school website for information about average SAT scores and things like that. To give you an idea of what Mac expects to see, here are my credentials:
GPA (W): 4.5 out of 5 (I think…I was always confused by how they calculated GPA)
SAT: 610 (M), 730 (W), 700 (CR)
ACT: 31
Class Rank: somewhere in the top 10 out of 200
Weighted Classes: AP Human Geography, AP French, AP Lit, AP Lang, Honors French IV, plus some accelerated classes my freshman and sophomore years.
Extracurriculars: Red Cross Club, Quiz Bowl, NHS, Tri-M Music Honor Society, Wind Ensemble, Math Team, French Club, 4-H, volunteer work, private flute lessons, Concert Band, Pit Orchestra
Letters of Recommendation: I assume they were pretty good, as I liked and did well in the classes of the two people who wrote my recommendations
Essay: I was happy with it
Of course, there were some obvious weaknesses in my application. My SAT math score was low, despite the fact that I took the test three times. While my list of extracurriculars is fairly extensive, I joined the majority of these clubs my senior year of high school. Apart from music, there were no activities I was involved in all four years of high school. Also, I only took 4 AP classes in total. Many students here have taken 5 or more.
I did well in high school, but not as well as some of my peers. The reason I’m mentioning all this is because Macalester really seems to value character above numbers. They love people who are creative, motivated, socially-aware, and determined to make a difference in their education and in the world around them.
For example, my personal statement was about one of my pet roosters who suffered from some unknown condition that prevented him from walking, and ultimately led to his death. Even though I couldn’t save him, I spent 2 years trying to nurse him back to health. I know this sounds like a weird essay, but it highlights most of the values I listed above: determination, eagerness to make a difference (even in the life of a chicken), and creativity (I’m not sure how many essays the admissions office read about a chicken infirmary). My supplemental essay was about some volunteer work I had done with a boy with ADHD.
My advice is to focus most of your attention on your essay, as it is the one opportunity you have to add a personal flare to your application. I completely rewrote my essay nine times before I ended up with a topic I liked. The key is not to choose a topic that is incredibly unique and creative, but to make even the most mundane topic SEEM incredibly unique and creative through your writing style, perspective, voice, and inquisitiveness.
I think your credentials will give you an automatic advantage over less-qualified applicants. However, in order to win Mac’s heart, be sure to tell them why you matter not only to them, but to the world at large.
I hope this helps!