I tend to toss a coin but if it's a major decision concerning me or my family I usually go with the 'gut'. Or I can always come on here and ask you nice people. : )
I usually follow my gut feeling but sometimes I don't know what it is. I find tossing a coin gets me in tune with that very quickly, usually before I've looked at whether it's heads or tales I know what I'm going to do.
That said, it only works for things that I have strong feelings on in the first place... anything I'm a bit blase about it doesn't work so well.