Volume for fine, straight hair

[VinoOlive]

I'm looking for some help how I could get some volume or curl into my fine, shoulder length hair.

I've always struggled to retain any curl through a curling iron etc, it just drops out really quickly.

Any advice on either a product or appliance to help?

Comb your hair the "wrong" way after washing it (while still in the shower). This gives me great root lift and brings out my waves, even though I don't blow dry my hair.