Best way to add volume to roots?

[Meta4]

Not sure if it's backcombing, or if there's some magical product out there.

I have Aveda volumising tonic but not overly impressed.

How long is your hair?
I have a puffy pink powder thing..might be Lee Stafford it works wonders..but only since I've had a layered shag circa Dido 2003.

this

Thanks, I get an error message but will Google it.

My hair's almost waist length but it's for an up-do.

Babyliss Root Boost.

Does what it says on the tin.