Discipline - What age and What type?

I have a DD who is 13 months old, walking since 10mths and fiercly independant. She has started to become more tempramental lately and I am thinking it is because she can't communicate what she wants. Although she does try very hard to talk - and some times a word will pop out clear as day then it is baby babble.

I also don't want to put it down to this and then find out later it was all just temper tantrums and I have left it to late to disipline her (disipline seems like a too harsh of a word but it is all I can think of at this stage).

At what age did you find that you needed to start disiplining and what options did you use. For me smacking is not an option as I don't feel like I would use it effectivly if that makes sense.