As someone with a lower GPA and very little upward trend (albeit from a competitive school with very little grade inflation), here are my suggestions:
Well, wait - my stats first. 3.38 cgpa, 3.17 sgpa, 35S MCAT. <50hrs college volunteering, around 600 hours of high school volunteering with much patient contact. Reasonably strong medical exposure (shadowing 160hrs, EMT training + 80 hrs clinical training). 4 years of research lab work. Plenty of hobbies and some leadership.
Okay, back to the suggestions.
Know that you are fighting an uphill battle. GPA is one of the single most important factors in medical school admissions. I'm fairly confident in saying that at some schools, admissions will discard your secondary application based on GPA alone.
How to counter this:
1) Apply broadly. I applied to 13 DO schools, 31 medical schools total. Received 4 interviews, 2 acceptances. It's expensive and tedious, but just do it. This is the price paid to try and get over a low GPA. You can always take a post-bacc, but I would say that's a worse option than just getting in. Although it may help you, there's no guarantee that you'll get into a medical school after a post-bacc.
2) Make the non-academic portions of your application as strong as possible.
Get shadowing experience. I would say that shadowing a primary care doc is best (or at least something to consider) because they'll have the most time to devote to you. While something like emergency medicine is exciting (EMT training was one of the best experiences of my life), an ER doc might not be able to even look at you if the shift is getting slammed.
Volunteering is also big. Get it in. If you don't have much clinical exposure, focus on getting into a medical volunteering position. My friend volunteered in the burn unit of our local hospital and had constant patient contact. Otherwise, I think there's something to be said about volunteering in areas you love. Cooking is one of my main hobbies, so I jumped on the chance to volunteer as a prep cook at the local soup kitchen. While this is a little risky, if you love it and truly want to help, I think that people will notice. Some schools place significant emphasis on this.
Hobbies aren't huge, but they can help. Medical schools don't want to see an academic robot (well, not all the time). They want to see an applicant who is academically talented but also lives a rich life. Leadership opportunities frequently come from these.
Yes - leadership is a big thing as well. This is difficult to obtain on short notice. You can find leadership positions in hobbies, work, or even through things like being a camp counselor.
3) Research. I gave this one a separate category because it's slightly different from other non-academic activities. Unlike the other things, some schools value it, some do not. I know that a representative from CCOM straight out said that it would not hurt you, but that they personally did not consider it to be an important factor when judging applications.
The other thing is that you can get credit or money from working in research. Something fun to think about.
4) MCAT. Ah. yes. Don't shoot for 27 or whatever people tend to say. Shoot for as damn high as you can. Yes, you can make it into DO school just fine with a 27, but remember - an applicant with a low GPA needs all of the help they can get. Shoot for over a 30.
Don't be scared of the test. Embrace the challenge. It's standardized and therefore fully predictable. Realize that all of the material is stuff that should've (or could've) been covered by the end of the sophomore year of college. There's no upper-level science on it. There is no reason why you can't do well.
On the other hand, in my limited experience, people who don't like to read for leisure tend to do poorly on the verbal section. I think that it's easier to raise an MCAT science score than to raise a verbal score. I'm not sure how to tackle that problem since I read quite often. I would say to try to read more while simultaneously doing verbal practice problems.
In my opinion, the most important thing is practice. Buy practice problems from your test company of choice and from the AAMC. Everybody learns differently, but I loved my Kaplan prep materials. I did not take the course and studied on my own. From what I've seen, successful MCAT takers study for at least 2, usually 3 months. It doesn't have to be super intense - maybe 1 or 2 hours per day, but you should try to at least do a moderately thorough review of the science/verbal material, then do as many practice problems as you can cram in.
5) Finally - interview day. Again, be impeccable. This website has interview feedback (link at the top of every page), so there's no reason why you shouldn't be fully prepared for every single interview. Schools don't want to waste time with interviews, so it's logical to assume that every single person invited has a chance to get in.
If you're an awkward person, you need to fix that. Start talking with people - waitstaff at restaurants, cashiers at stores. Go to random conventions and just start chatting it up with people about their hobbies - who doesn't like to talk about what they love? They say that the most successful interviewees are the ones who present themselves as 'comfortable in their own skin.' A person who comes across as sincere and articulate will be memorable to interviewers. The easiest way to come across that way is to actually be sincere and articulate.
6) The icing on the cake - knowledge about the field. You will have to know, at the very least, the general history and philosophy of osteopathic medicine. I personally think it's important to delve far deeper. Get thyself to the local library and start reading - healthcare policy/public health, economics, ethics. Autobiographical pieces by doctors, patients, med students. Read it all. Nothing in this world is black and white. You aren't going to simply go to work, fix people, and come home. There is so much that is going on. Google pre-med reading lists. You'll find a lot of good stuff.
Whew. That was longer than I thought it was going to be.