Specifically talking about ば、なら、たら、and と here.

I just read Derek Schaab's excellent reply to [this question](https://japanese.stackexchange.com/questions/393/differences-among-%E3%81%9F%E3%82%89-%E3%81%AA%E3%82%89-%E3%82%93%E3%81%A0%E3%81%A3%E3%81%9F%E3%82%89-%E3%81%88%E3%81%B0-etc) on when to use the different forms of conditionals -- something I'm really struggling with at the moment. But that is a lot to remember when you're trying to select the correct expression in a conversation. I expect that most Japanese aren't even aware of these rules. 

So I was wondering, are there simpler rules that get you the right answer most of the time, and, if you do use the wrong word, how much does it actually matter? Will you be completely misunderstood, shown to be the foreigner you are, or anything in between? 

Any tips on how other people have approached this learning problem would be appreciated.