how to I test my soil ph accurately?

My problem is that I'm essentially in the dark when it comes to soil and water ph levels, I have two ph testing devices (one is a probe stick from walmart and the other is the liquid with vile tester), but I can never get an accurate and consistent reading from either. first of all, my probe stick never gives any reading (regardless of what I'm testing), and secondly, my other ph tester gives me different reading every time (despite it being the same test sample.

Is there any advice on what I may be doing incorrectly, and how I might, for once, get a reliable reading?

Thanks.

Throw away that thing with the probes, they're crap. I had one, all it ever read was 7. U can either shell out the dough for a good electronic meter, or use the drops to check the runoff of the soil when u water. I use the kit from general hydroponics, with the drops and the vile, and it definately gets me close enough.