I do my hair in the morning. I rinse upside down, apply products upside down, gently squeeze out excess water with my microfiber towel (some product gets squeezed out but it's mostly water) then plop for no more than twenty minutes. I diffuse with warm air for 20 - 30 minutes then I let it airdry the rest of the way. When I don't diffuse and just let it airdry, it does end up pretty flat. The heat doesn't do that much damage to my hair.
Curlygaladi, I'm thinking maybe you are plopping too long. If I plopped for an hour my hair would be nothing but frizz. Twenty minutes is the max I can go. Just a suggestion!