I've always used the scoop method for backing in. Similar to the Z method but starts on the far right. Really helps to get the TV and 5'er aligned with the spot prior to backing up. We fought backing in until we found this method. Now we're in our tight storage spot often on very first try. We're inexperienced rookies at this too!
Biggest mistake I learned was to straighten the tow vehicle much earlier with a 5'er than when backing a trailer.
http://littleguy.vanillaforums.com/discussion/2896/how-to-back-up-a-trailer-easily-the-scoop-method-of-backing