If your hair naturally frizzes or curls, another trick for how to have straight hair is to combine straightening with good hair products. For thick or brittle hair, argan oil is ideal for nourishing your lengths for healthy and supple locks*.
However, if you have thin hair, stay away from oils and products that contain silicone. They can weigh your hair down making it look limp and tired. Instead, choose a serum or spray that lightly holds your hair. Rather than applying it directly, you can spray it onto your brush. That way, you can comb the product into your hair evenly without making it sticky or stiff.