Isaac I said 'No'

Isaac I said No.....No Isaac.....No......I can say it until I am blue in the face but my 14 month old son seems to revel in the entertainment and even find it mildly amusing that I attempting to stop him doing something that he is enjoying. I don't know whether the fact that I'm saying no is feeding his behaviour and positively reinforcing it by providing him with attention or whether he doesn't quite understand what the word means...although I'm pretty sure its the former rather than the latter.  Either way, I seem to be adequately failing at disciplining him already and I fear the future will not be bright when it comes to saying 'No'.

In addition to refusing to listen to me and pretty much disobeying my every command he's also starting to have mini temper tantrums and gets very frustrated if he can't do something after one or two attempts. The problem I have is that the temper tantrums are mildly amusing for me, except when he decided to hit me in the face when I took his dummy from him the other day. When I told him off he just looked at me as if to say 'What'!

I always thought I would be quite good at discipline as my niece and nephew always seemed to listen to me when they were little, however it seems that I am becoming the person I never thought I would....my mother!!! My mum was never very good at disciplining me and my brothers and generally left the telling off to to my dad as his stern look made us stop in our tracks before he even opened his mouth. However, on the other hand, we generally ignored my mum as she laughed/smiled when telling us off so it didn't really have a lasting impact on our behaviour.  I do try not to laugh when I tell Isaac off but I obviously don't have an impactful tone to my voice as as soon as my husband says no, he gets the quivering bottom lip and tears. I feel the disciplinarian in me needs to be nurtured or I fear my one year old will be running riot before he is two years old! 

Has anyone got any tips or advice on telling one year olds 'No' without reinforcing the behaviour and encouraging it?