Do you mean a straight across fringe or side ones? If it’s more to the side, swept-over-to-one-side styles fixed that problem for me years ago (Miranda Kerr wears her hair like that a lot), curls can help as well as they add shape and pick them up a bit. If it’s straight across your forehead, your options a little bit more limited; until it gets longer or at least until the stage that you part it through the middle, bobby pins are your best option unfortunately!