del

I think you have a great shot, a 3.8 GPA and 1590 SAT is great. You can absolutely transfer from IU to a top target, I've seen this happen before.  As mentioned above your focus should be getting a 4.0, take the easiest classes possible: for transferring, nobody looks at the rigor of your classes since AO's can't parse the class data like they could in high school. I would join 2 clubs preferably in econ or finance and maybe do some voluntary work bs to show that your humble. Other than that, the kids who had a shot of breaking into T20 in highschool will ultimately be the ones that end up transferring. Here's a list of transfer friendly schools to apply to: USC(west-coast target), Northwestern, Columbia, Brown, Georgetown (admissions have been pretty low though recently). Check out Cornell and Upenn econ as well but they have certain credit reqs to  look out for.  

Just some other advice as well. Highly recommend trying to build relationships with TA's and professors as you'll need to get recommendation letters. Don't just ask for  a rec near the deadline. Be the one to participate in sections or class and make sure your professor knows your face and name. Kiss their ass and suck their dick - that's how the games played. And make sure your finish apps during winter break and not during the spring semester.