How to scrunch my hair really good?

I have pin straight hair , i have some waves but not really like i want it . Ihave garnier fructis scrunch gel and curl enhancing mousse , ialways put my hair up in a bun and do everything over night. My hair is really hard to scrunch and any suggestion of what to do? different kinds of techniques? i really want my hair scrunched . No diffuser please i dont have one