A couple of times everyday... it aint hard? You just line yourself up close side mirror to side mirror next to the car you will be parking behind... turn the wheel entirely to right, back in until you are in "\" shape (diagonal), now turn the wheel entirely to the left and back in... yay.. :)
I do it probably once or twice a year. I'm pretty decent at it. The key for me is pulling forward as close as possible next to the car that would be in front of me. Then when you back up and half of you car is past the back end of car next to you, start turning your wheel to get into the spot. The rest about familiarity with your vehicles size.