Some paper crafts require folding and then cutting in shapes. The problem is that the unwanted folds remain visible. Assuming that the paper can be opened fully, what should be done to remove the fold marks on the paper?
The paper fibres are broken. The damage is one-way. There's no going back once the damage is done.
But while you can't remove folds or wrinkles from a sheet of paper, you can leave wrinkles and folds behind.
Make a pattern by folding, wrinkling, cutting, etc. Then, use that original as a pattern to trace onto flat, unwrinkled, and clean unfolded paper for the final finished product.