How to get really good, straight hair with an iron?

I have shoulder-length curly hair that I straighten regularly. However, I can't seem to get the straight ';edge'; at the bottom; my ends always turn out or in. Is there a special technique or product I should use?? Also, do you have any suggestions for product to use when straightening my hair?How to get really good, straight hair with an iron?
Blow-dry your hair, Really good!! Not just passing it threw get a circular brush and round your hair around and wait till it dries on every piece of hair. then straighten..How to get really good, straight hair with an iron?
Like the previous post says you should blow dry your hair first with a round brush. But before you do this add a very small amout of serum. Bumble and Bumble, aveda, and kerastase are all good serums. Make sure you dont use too much because it will make your hair oily and weigh it down. Also, when's the last time you had a trim? Nicely trimmed ends usually lay nicer and look a lot healthier. If you blow dry your hair first, use the serum and your ends still turn in or out then try using a curling iron to bump your ends under.
I have straightish wavy hair that i straigten and i cannot get it straight at the bottom either but now it help when i use straightening spray/gel as soon as i get out of the shower then blowdry my hair and straighten then the next day you don't even need to shower if you don't want to just touch up the straightening and spray/gel again!
when flat ironing your hair part your hair in little sections at a time it will give you a better straightening
flat iron spray is a god send.
use a hair serum that's good for curly or straight hair....
i agree flat iron spray is the easiest