Step 1: Start With Letter Sized (or A4) Sheet of Paper.
Step 2: Fold One Corner Underneath Fully As Shown.
Step 3: Unfold Same Corner.
Step 4: Repeat Mirror Image.
Step 5: Unfold Again
Step 6: Fold Through Centre Where Fold Intersects the Point of Intersection of Folds 2 & 4.
Step 7: Unfold All and Begin a "butterfly Fold" of Sheet As Shown.
Step 8: You Should End Up With What You See Here.
Step 9: This Shows the Reverse Side of That Same Fold From 8
Step 10: Fold the Corner of This Newly Formed Flap As Shown.
Step 11: Repeat Same for Other Side.
Step 12: Fold Pockets.
Step 13: Crease the Sides of This Box Down.
Step 14: Finished Step 13.
Step 15: Same As 13. and 14. for Other Side.
Step 16: Fold Corner of New Box Up Into Opposing Corner.
Step 17: Same for Other Side.
Step 18: Fold the Envelope Tongue
Step 19: With Some Luck It Should Look Like This
Step 20: Fold Nose Over.
Step 21: Tuck Nose Under Tongue
Step 22: Tuck Underneath
Step 23: Voila. Getting Close.
Step 24: Fold From Sides.
Step 25: Same Other Side.
Step 26: Fold Corners
Step 27: Fold Other Corner
Step 28: Tuck Under Previous Folds
Step 29: From: Flap
Step 30: You Can Address and Stamp the Other Side and It's Legal Postage!
pushingtheenvelope.jpg has my howtoon graphics and should hopefully print correctly to letter sized paper in portrait format.