2 kids.
Be patient.
Make them understand there are rules. And breaking rules have consequences.
Constantly yelling at them does not accomplish anything.
Pick wisely when to be hard on them and when to encourage them. Every kid is different so there isn't a perfect template.
Don't be afraid to spank your kid, but if you're doing it too often, it's not working.
Most importantly, be consistent.
This right here...be consistent and firm early and that will make the latter years much easier...I have to constantly stay on my youngest son about stuff and when it escalates to spanking, I go right back to him after a few minutes and explain how we got to that situation and then explain (or make him explain) what he could have done better to avoid it
But like the poster said above, pick wisely when to be hard and when to encourage...
Remember, they don't have the same vocabulary as you yet, so don't get frustrated when they can't explain things to your liking.
Also, let them fail at stuff sometimes (but still encourage them) so they will learn how to handle it....
And they are like elephants...they remember EVERYTHING you say so don't be saying you will do this or that (and don't really mean it) or they will call you out on it with the quickness...
. Moon bounce in the living room
. Little roller coaster in the basement. 
to you guys for being a good father and so much respect for you guys. 


. my advice:
Damn bananas and strawberries do enough.
....but I also play with them, read to them, and show them new experiences as much as possible. Coolest Dad ever, but don't play with him is how i'd be described