set a lower F-stop (if you read the manual a lower f-stop gives you a sharp foreground but a blurry background, ideal for portrait shots and a high f-stop gives you a sharp(er) back and foreground. Google depth of field. Oh and use manual focus or point focus.
Depending on your shooting conditions you may need a tripod at higher f settings, having a remote is also a plus. If you have any other questions ask them here of shoot me a PM.
99% of the time I'm in Aperture priority (A) and the remaining 1% is Shutter Speed (S).