I used to make one like the square plane, except at step 4 I would fold the outer points on more time toward the center line then fold the tip while inserting t

I used to make one like the square plane, except at step 4 I would fold the outer points on more time toward the center line then fold the tip while inserting the previous folds into the folded tip so it makes a thick triangle. You could then fold the wing tips up or down to make the vertical surfaces. I'm not sure I'm describing it well.