How can I improve my fine hair?

I have very fine hair, baby fine really. It is very difficult to style as I like it to be shoulder length and just don't suit hair any shorter. Does anyone have any advice re foods and supplements or hair products I can use to improve the texture/thicken my hair? I am 44 and am wondering if it has anything to do with going into the menopause? Any help I'm very grateful for. Thanks.