I've always followed my heart but have regretted quite a few decisions I've made. Maybe I should start to think more, but how do you stop following the heart?
I think you have to do a bit of both, if you always go with what your head thinks and regret it then you should try doing it the other way, what is the worse case scenario? if you can live with it then its a risk worth taking.
life is a rollercoaster you have to experience the highs and lows and sometimes you have to jump out of the comfort zone to do this..
I do both and sometimes its the wrong choice other times it works out okay, whatever the result its a lesson learned!
I think it depends on your age but my advice would be use your head for the important stuff like who to marry and your heart for the trivial like what flavour icecream.