How can I scrunch my hair over and in the morning easily?

my hair is pretty straight, but i has a slight wave too it. i would like to scrunch my hair more often, but i can never get it to hold and it has A LOT of volume when i do it. my hair just poofs out but it's flat on the top of my head...please help me, and i would love answers of how to do it in the morning and night, and if you could possibly do it step my step and be specific on what products you use, thank you