It's also important to have plenty of wrapping paper. Don't be afraid to "waste" it. That's kind of what it's for.
Solid paper shows errors, but paper with an intricate design pattern will hide flaws.
Just get those first two tape-downs correct, on the center. Pull one side over and tape it to the box. Pull the other side over and tape it, too. At the center. Once you've done that, the rest is just detail work, and forgivable. If you get the first part nice and tight, it helps a lot.
You've probably already tried the following short-cut, but here goes, for those who haven't:
If you are really helpless, get pounds and pounds of nice, thick, ribbon which can be curled. Then, cut your wrap job short after the first two folds discussed above. Flip the gift over so the seam in on the table. Then, use your cool ribbon to gather and bind one end of the gift at a time, like wrapping a piece of candy. This is a compromise, but if you attach a bag of candy, well, then... it goes with the theme. Here is a drawing: