Umberto Giannini Glam Hair - Backcomb In A Bottle. I picked mine up at Boots for around £5
The only way to demonstrate it is with some really embarrassing photos - I wanted to give you guys a good idea of how it works so please excuse the awkward poses and cheesy grins!
Firstly I start with incredibly flat looking, just washed hair.Then I use my GHDs to straigten my hair and then curl it under as I get towards the bottom third. The waves give it a bit more movement and add to the volume. Then I spray individual sections with Backcomb In A Bottle.
Next I tip my head upside down and massage it into the roots, in the final picture here I have messed up my parting and set it with good old Elnett hairspray.
The product stays in pretty well, but I do use quite a lot of hairspray. It is also easy to scrunch the hair during the day to add more volume and the product that is already in the hair tends to hold it. It is quite versatile - I even use this when tying my hair up as it gives it more of a messy look. Best of all it is easy to brush and wash out, fabulous not waking up looking like Russell Brand after a night out ;)