What are some tips for standing your ground on a topic when you KNOW you are right and the answer is important?

If it’s with your SO, write it all down, explain where you stand, and hand it to him. It won’t feel as confrontational to you, and you’ll be better able to ease into being able to stand your ground next time. Tell him that this is how you’re going to work it with him next time, and please remember to take your note seriously.

In the rest of life, you’ll just have to do it.

Consider it a lesson for both of you and move on.

For big decisions the both of you should take a day or so and write down the pros and cons then discuss. That gets the idea of things having more than one opinion and gives you a chance of getting your side if the discussion out there.

Before giving in, say that you need more time to think about it. Go away, review your research and muster your arguments. Then present them to him logically and give him some time to think and respond. Talk to yourself about why you are inclined to give in.

I am negotiating the rest of my financial future right now with a lot of emotion surrounding it and am surprising myself by how businesslike and logical I am able to be in the crunch.

@keobooks – I’m diametrically opposite from you in behavior—when I think I know the right choice I am almost intractable and take a LOT of discussion (with my hubby) in order to hear another option…but perhaps in that way I’m more like your mate, and you are more like my mate, who is very conflict adverse. I’m happy to debate and fight for my choice..he dreads this horribly.

I think the most telling sentence in your question above is this one: “I felt pressured to go with his choice.”

The next time you’re in this situation try stating your feelings (“I’m feeling pressured to make a decision.” or “I feel like you have your mind made up about this, but I’m not so sure.”) and/or stalling for time.
It seems to me that you don’t want to confront the other person, so you give in.
If you don’t like confrontation, the best thing to do is to ask for more time or another venue so that you can (when you’re ready) present your research. Anything that isn’t life or death urgent can wait, can it not?

This is your first step you recognized your problem and changed it. Celebrate a small victory. And keep in mind the good feeling. Also remember you might make a mistake or start floating the other direction its ok. It’s not the end of your life and you can adjust your response.