Place the letter face up on a flat surface
Fold the bottom edge up to the top edge
Press the fold firmly to make a crease
Fold the letter in half again if needed to fit the envelope
Insert the folded letter into the envelope
Place the letter face up on a flat surface
Fold the bottom edge up to the top edge
Press the fold firmly to make a crease
Fold the letter in half again if needed to fit the envelope
Insert the folded letter into the envelope