I actually timed myself to straighten my hair and it took me just 20 minutes.

I always shower the night before, and then put my hair in a ponytail at night to air dry and then straighten it in the morning. I use my Ultra CHI flat iron and CHI silk infusion as heat protectant (sometimes tresemme heat tamer spray).
I never blowdry my hair. Air drying makes my hair smoother and it's one less heat I'm using.

My hair is 2b-2c and is almost passed my boobs.