Hairstyles for straight fine hair

The combination of straight and fine hair is very challenging - that's what I have too. After a lot of experiments I'd say the most suitable cut for it - the bob style. Depending on the shape of your face you would choose the length.
If the shape of your face allows - make it a short bob - long enough to tuck your hair behind the ears. When I had short cut I found that wearing hair behind my ears made it look like there is more hair.
If your face is round or heart-shaped - go for longer bob.
If your hair is fine and thin (meaning that not only each hair is small in diameter but also there is not that many of them) - layers are not for you. Even though stylists say that layers give a volume, but seems like on fine and thin or thinning hair they are not defined very well and just make the overall appearance even thinner.
If hair are fine but there are plenty of them - well cut layers might help, there shoudn't be too many of them though.
Another approach, if the age allows, might be a very short cut with a bang. It will look good on younger person with more or less good skin as it will drag attention to the face and eyes.
No matter what cut you choose  - important thing is - keep it trimmed at all times. The fine straihgt hair, especially thin, look terribly unattractive when starting to grow out of shape.
While there are lots of styling solutions made to pump your volume - go easy on them. I usually wear shoulder length hair without any styling products on them. Even on special events I do this:
 - wash hair with Amplify shampoo and put conditioner just on ends;
 - comb while wet (here is a trick: naturally I have part on my side and I noticed that my hair become so thin there that it starts to show scalp, so while it's wet, I comb my hair creating part on the opposite side and let it dry that way);
 - then I use old-fashioned plastic hot rolls on completely dry clean hair without any styling stuff. The trick is to put them on the ends only so there are no dividing lines in the roots area, not too tight and not on the same line: go one higher - one lower. Wait until they are completely cold and take rolls off. Don't brush your hair, just put your head down and shake it. You will get nice, a bit messy volume that has natural move and doesn't get sticky or oily after you touch it.