M.G.
Volumizing Shampoo all over. Volumizing conditioner only on the very ends (conditioner weighs down hair).
Flip head over (like lean way over) when you blow dry till it's just about done.
Roller brushes - roll hair around brush right up to your scalp (think big roller) and hit with heat. Leave brush in your hair for a minute or two as you do another section with another brush. I have three brushes, I roll up one section of hair, blast it with heat, then roll up another, go around head. I use BIG brushes to get lots of volume. It comes out looking like you've had huge rollers in it - big bounce.
I use Bumble and Bumble volumizing spray. Any kind of volumizing product should work though - the key is to get it on your roots mainly and just comb through. Don't use more than a dime size amount if it's a cream or gel type product, or about 6 good squirts if a pump. Lift hair in sections to really get it at roots.
If you're into hairspray, you can spritz your hair with your head hung over upside down and then hit it again once you're standing upright. I haven't done that in years, but used to gift it lift.
Good luck :)
Oh - and a layered cut works for me - I get way more body if it's layered on the bottom (long layers).