If you have really fine hair like me, you probably just want so volume. I always use some volume spray before I blow-dry my hair. And: I always spray some sea salt spray into my hair. Just put all your hair infront of you and put some sea salt spray on you hair. Flip it back and ruffle you hair. It gives you a nice volume and nice beach waves if you put you hair in a bun before.
I love the Beach Baby Salt Spray from Lee Stafford. They have amazing hair products and are not that expensive. The Sea Salt Spray costs only 10,95€. You can find it on many online stores. I bought it from a german online shop, but you can also find it on Boots.
I would really recommend you to use sea salt spray if you suffer from fine and flat hair.