I, too, have been guilty of allowing my heart to rule instead of my head in the past. I have also allowed things to progress too quickly and when I've done that, I have always paid the price. What I have learned from this is that even though you are caught up in the attraction and the rush that goes with it, you still need to take a step backward and see the big picture instead of what is just in front of your nose. Trust your instincts. Listen to this person when they talk and hear what they are really saying. Watch this person and see who they really are as they interact with the world around them. Observe how this person lives and see if they are responsible and sensible or if they have habits that will make you want to run screaming into the night. Pay attention to their friends. People usually attract like people. If you don't like the friends and there seems to be a common thread connecting them, you may be seeing something that is also present in your person of interest. Be wary of inconsistencies and a lack of willingness to be open and honest about people and past events.
It's hard not to rush in and throw all caution to the wind, but when you keep falling flat on your face, you need to rethink your strategy and move a little more slowly. Usually, after a few dates, you start to get a real feel for who the person is and to see if there is real chemistry there. Like the traffic sign says... proceed with caution.