help me out!!

hey everyone,
i have medium brown hair about half an inch above my shoulders. *finally* anyway ive been keeping it straight with that phyisic (not spelled right but we arent here for spelling) well its been a real pain lately. it seems to shrink from the humidity (my guess)..is that even possable?? And my other question that i really want an answer for is, one of my friends scrunched her hair during the school year and now that its the summer break i figured id give it a try since i wont see her often. What exactly do you do when you scrunch your hair to make it have that toussled curly but not curly curly look, a little bit like the Olsens twins but not as curly.......if you get the picture can you please please please let me know how you think it will look and how to do this style!!!
thanks sooo much!