Hair Voluminizing Tips???

My hair is fine but fairly thick and has some volume.

That's the best pic I can find lol. That's my hair natural and air-dried with no product in it. I lost a lot of hair and volume the first 6 months after my son was born. I'm sure it'll grow back but for now I'm looking for some tips to spruce it up every once in a while. I plan on chopping a few inches off in the near future. I'm also willing to spend 15 minutes or so on it, but nothing like curlers. I'm willing to do product and blow-dry for example. Does anyone have any advice on what I could do to add a little volume to my hair sometimes? TIA!