I've learned when I am reacting emotionally to something, to take the time to work backward from that emotion to find the thoughts that are driving that emotion. That way I can decide whether my emotions are based on rational thinking or if they aren't and work from there. Generally, the stronger and more intense the emotional reaction, the more irrational the thinking behind that reaction is (for me anyway).

Do I manage this successfully every time? Heck no! But it is something I keep working on and it does help when I can manage it successfully.