These steps are the same for all types of pleats.
Pinch Pleat—Divide the large pleat evenly into three smaller pleats; press in firmly and stitch across the three folds at lower edge of heading. The Pinch pleat is a favorite finish for most types of draperies and is particularly good when draperies are made of a heavier fabric.
French Pleat—At lower edge of heading, divide large pleat into three smaller pleats and run needle and thread through three pleats several times, drawing thread tight. Then fasten thread securely underneath.
Box Pleat—The large pleat is spread an equal distance on each side of stitching and pressed flat. Box pleats should be about 2″ wide, taking up 4″ fullness.
When figuring these pleats, try for uniformity; that is, the space between each pleat (from fold to fold) should be the same as the width of pleat. Box pleats should be about 2″ wide, taking up 4″ fullness.
Cartridge Pleat—This is a round pleat left loose and filled with cotton, Kapok or a roll of stiff paper. The pleats take up 2″ to 2½″ and are spaced from 2″ to 3″ apart for draw type draperies.