Prospects for IR/MPP (Idev Policy)

I'm new on this thing, so I hope I'm doing this correctly.
I am looking into making a career change from finance to public policy/IR, with a focus on international economic/social development. I want to know what I should focus on to get into MPP/IR programs at UMich, Georgetown, SAIS, GWU, and SIPA. Regarding my numbers, I took the GRE once, but didn't do as well (really busy with work). I got a 6 on AWA, 600V (82nd percentile) and 660Q (65th percentile, lost stamine by the time I got onto Math). So I plan on taking the GRE one more time, particularly to focus on my Quant. I have a 3.6 GPA in Economics and History (specialized in Middle East) from a good public school and I've done really well in all my Econ coursework (Micro/Macro/Econometrics).
As far as my work experience and travels, I was raised overseas in a developing country (which sparked my interest in Idev), and moved here to the US alone for higher education. Since I've graduated, I've been working as a financial consultant in the private sector for almost 3 years which has given me a great skill set and solid project management experience. In addition to my full time work, I have been continuously volunteering by helping local refugee communities as a mentor and academic tutor as well. Now, I plan on going to Africa for some time to get hands on community development experience and help NGO management before I apply to graduate schools. Also, I am fluent in 2 languages, and have basic knowledge of one. Are there any suggestions you guys have for me? Any feedback would be tremendously helpful:-)
Thank you!</p>