I am with easilybored here.
With ds1 I bathed, shaved, plucked, buffed, clipped, moisturised etc whilst in early labour.
Straightened hair. Lick of foundation and mascara.
Pah, I thought, I'm not looking completely rotten in hospital.
It was only when, in hospital, I handed my poor dh a soiled sanitary towel to dispose of did I realise that I just didn't give a shit anymore 

I am mortified now every time my dh mentions it.
I was prepared for ds2 labour!
If you're taking straighteners though, just take your usual. But check you're allowed them before taking. Good luck!