I've tried many products on my hair to add more volume (including lots of teasing and hairspray) and it wasn't until I started using volumizing shampoo and conditioner that I really got results. So, if your hairspray, gel, mousse, etc isn't doing the trick try one of these products that I love.
Big and Sexy Big Volume Shampoo and Conditioner
This product adds volume and smells great...the first time I tried it I got the travel size at Ulta which is convienent....I love great travel size products, and I like getting sample sizes of products the first time I use them so that I can try them out.
Bumble and Bumble Thickening Shampoo and Conditioner
This product really adds a lot of volume to your roots. I don't love it for everyday use, but for every few days or using it on the day of an event you want volume for it is awesome! And good news, Bumble and Bumble is sold at Sephora now in addition to select salons.