The most effective way to master parallel parking is to practice. Many behind-the-wheel driving tests use cones. To begin, set up the cones in a deserted lot or very quiet street with little traffic. A spot that is 5 feet longer than your vehicle is ideal for practice. Once correctly parked, your car is 5 to 8 inches from the curb, although in some states, 12 to 18 inches are allowed. You may live in a place where you never need to parallel park, so don't skip other important aspects of driver such as merging onto a highway.
Watch out for ice and snow? If possible, do road tests on Weekends where you don't have to worry about school zones at all (I've seen at least 8 different times periods for school zones in our city alone). Stay in lane when doing right and left hand turns (I got points off myself for making a left turn too wide). Be aware of construction zones and other road problems. Try and follow another person that's doing the test so you know what to look for (although this might or might not work, for obvious reasons). Watching speed is one of the easiest things you can screw up on (has happened to all of my friends for some reason). Make sure the car is in good working order and isn't making any weird noises before you actually drive (I actually did about 4 different errands in my car 4 hours before I took my test).
And just relax? I was actually pretty mellowed out and sleepy by the time I was actually scheduled to take my test; make sure you're actually awake for the test. My brother just passed the road test here in MN 6 months ago. Main things are parallel parking, 90° backing into a parking space, one-way streets, and parking on a hill. Do the parallel & 90° in as few moves as possible, I think you can redo the whole procedure if you feel you're not doing it well enough, but if you hit a cone you automatically fail so go slow & be careful.