Some settings I can tell you that should help are acceleration settings. These are found under the configuration section in the control panel. I set both x and y to 900 print, and 800 move. Also making sure your are extruding the right amount of filament can make a big difference. I found a formula online, (100mm / extruded amount) * current e steps. This was not that easy for me to do, and I got it to work once kind of.

For me printing a ring with a specific inner and outer dimension and measuring the results made it far easier to dial in my extrusion. As of today I am printing with in .1mm of dimensions inside and out, and not only are the prints more accurate wich is great for making parts. But the walls of the print come out much cleaner versus over extruding. I did however also find out with the ring test that my x and y are off a hair, not moving the same distance gives you a inconsistent circle. I would have never known if I didn't spend all that time calibrating my extrusion with rings. It cleaned up my corners too.

I would also recommend the z axis brace mod found here. http://www.thingiverse.com/thing:921948 Cost me $15 in parts, and a few hours printing. Install was super easy, and this has made a huge difference in my printer. I went crazy the past week or two, swapped out the y carriage for a 3mm one with 3 point leveling. (haven't setup the 3 point yet but plan too) Z axis braces, printed bearing block all around, and a new y axis belt tensioner to allow the use of the new y carriage. New bearings, a few fans, a bunch of zip ties lol! Parts keep showing up at my door, still awaiting a few things lol. I got the bug big times.