Probably the most trouble-free, easy way is to run a cylinder balance test. If you have a code reader, all you do is run the KOER test, then when its done, blip the throttle, and it should start revving by itself and whatnot. It shuts down one injector at a time and looks for differences in RPM. If you have a dead or badly clogged injector, there should not be a large drop in rpm on that cylinder. Then, it'll tell you which cylinder(s) is/are the culprit.
If you run this test several times, and it comes out good every time, chances are your injectors are fine.