1)  Fold the sheet in half, then unfold. It's suggested to face
the convex side of the crease up as shown, as this will preserve
its direction in the finished airplane.  
2)  The angle and position of the main diagonal folds (two symmetrical
folds, the first of which is shown above) can be varied in the
Dragonfly to get an interesting range of finished airplanes.
These folds will be the leading edges of the rear (main) wings.
Note that if these folds extend beyond the centerline an unnecessary crease will be visible on the front wings, which won't happen if it's done as shown
Their position and angle affect the size and shape
of the front canard wings in a predictable way,
which is detailed on the next page.
Images, Text, and 3-D Forms Depicted 2001 PaperAirplanes.net