Rotation for levelling Demonology Warlock

So I am levelling a Demlock and was wondering if anyone had any advice on spell rotations?

I've googled me heart out and all I can find are pre-Mist guides, or guides aimed more at end game 'locks with spells I can't even dream of having right now.

She's at level 15, and I just need to know the best progression so I am properly learning how to play her, and growing as she grows :)

Thanks.