Yes I have, but it's genuinely hard and rarely happens without conscious effort. Particularly in forums I've seen topics being debated for 8+ years now and normally you see each person become more entrenched in their own opinions than changing to reflect others.
A big part of why I've sometimes changed my opinions is, despite being confrontational, I also have a fear of confrontations and it's incredible just how much backing down in an argument engenders good will on the other side. Someone did it to me first, we were having a flaming argument on politics and I was call him a blood sucking tory vampire etc and suddenly he complimented me on the insults and said he'd enjoyed them and thought they were pretty clever and wham, suddenly we were both doing our best to find every possible part of our opinion that we could compromise on.
And the technique has been effective ever since. It's only not worked once or twice (and normally you have to get reasonably het up before you cue it in) and it's oddly frustrating when it doesn't. Wait a minute, I changed my opinion, you should love me and be looking for compromises, whats going wrong?
If you're looking for a way to/believe you can make fully rational decisions based on the genuine merit of the situation though, it's impossible/you're probably wrong with a very high degree of certainty. Our brains aren't wired for rational arguments and thinking that you're arguing perfectly rationally is exactly the sort of thing it tricks you into thinking. Its very hard to see it in yourself, but its very easy to see it in other people. Everyone can see that the Creationist absolutely certain the Big Bang didn't occur because 'thats like put a load of C4 in a junkyard and expecting to get an Apache Attack Helicopter' we can all see that he thinks hes being rational, but really isn't. When you're absolutely certain that there's no form of God, it's harder to spot that as an emotional belief.
I'm pretty sure the studies show that even when you're aware that you can't make fully rational decisions it doesn't actually help. You can try to draw up objective experiments, but unless the subject matter is clearly defined and objective itself, you#re going to find that you're drawing up and interpreting the results to suit your premise in subtle ways.
Maybe knowing that its natural to be entrenched in an opinion and natural to believe your opinion is rational helps when dealing with other people at least