Try not to do it daily, just flick the dryer over the ends to smooth them in the morning, or you could do like I do, I blowdry mine smooth, then flat iron it really thoroughly, make sure you use a good flat iron spray too, it usually lasts me 3 days after doing that.
If I do my aunts (hers is like pubic hair) I blowdry it poker straight then lightly use flat irons, she hates to wash it after iv done it because it stays straight until washed ( she's only lasted a week, but I'd love to know how long it could last)
Xoxo