How can i do thiss? ( pic includedd!)?

What can i use to do this? I want to make my hair very voluminous and poofy (kinda like scene hair) i love the way it lookss the way its teased. :)When i tease my hair it doesnt look right hhaaha. So yeah i want to make it thick and poofy looking without teasing tooo tooo much . but what should i do like should i buy volumizing shampoo,hairspray, conditionerr or what? haha and if so what brandd. after my shower in the morning i flip my head upside down put in bed head volumizing blow dry lotion and blow dry it which gives it volume and poof . but after straightening my hair and everything it falls flat after a while. the bed head stuff used to keep it like poofy and everything but it isnt working lately so any tips and suggestionss??? :) THANXX oh and pic of my hair if needed :