(As in actually open minded, not just comfortably sheltered from one’s narrow mindedness)

A technique I noticed while experimenting with being wrong:
1. If you have an opinion on something, find an opposing one
2. Feel like you believe it (emotionally, not necessarily mentally – pretend you know it’s true and don’t think about whether it is). It doesn’t matter how averse you are to it – if somebody else can believe it, there are reasons to (not necessarily rational ones). Think of that reason and try out the associated emotions. Feel loyal, caring and understanding toward the idea’s followers. The important bit isn’t the belief, but its emotional affects – feel something about it.
3. Stop.

Some justification for this touchy feely emotional garbage? To remove it from the equation.
I think the biggest fog over unbiased judgement is emotion. From a side of any battlefield there are fierce positive emotions radiating from your ideals and negative ones flying in from the other side. The correct side is obvious – the one supporting the good feelings! Open mindedness isn’t even called for. If it is brought out it is only to declare ‘I’m looking at the other side, and they look dangerous!’. But both sides are awash with emotions supporting them and driving them on. If they weren’t, there probably wouldn’t be an argument. Sound reasons devoid of emotional allure don’t pull the crowds. To be open minded it is necessary to neutralise of emotion. But it isn’t enough just to acknowledge it – ‘well the other side clearly cares about X’ – if you actually feel something for the arguments on your side. You have to feel both sides or none. There’ll be plenty of non feeling once you’re dead, and giving up feelings can be hard, so try for feeling both initially, as outlined above. It’ll all fade away quickly and you’ll be more open minded.

Note: do not necessarily think both sides are correct as a result. Just choose unemotionally, or taking all emotion into account.