@MissGremlin
Well, that's a tough one. I like to think about how I will feel about each choice. But not how I will feel now or when I make it, but how I will look back on it later. Which choice would I regret more.
I found that yes, you can weigh up pros I'm and cons of each option and try to decide on that, but that still requires deciding based on the now... and the now is so often hard to figure out. Everything always seems easier in hindsight... A when we can look back at choices we made. So I try to put my self forward day, a month, a year... and look back at the choice I have to make and think about how I would feel about each one of them in the future.
It's not perfect, and you can't predict what will happen in the future, but I find it helps me to take myself out of the now and gives me a different perspective to better see what is the better choice long term. Is this wisdom, or just my own little bit of self-delusion... who knows. I just know when there is a difficult decision to make, the more ways you can try and look at it, the higher the chance you can find the one thing that makes the difference in knowing what is the best choice.
Does that make any sense? I'm not sure it ever had to me, but I needed something in those hard to decide moments. The only other thing I found was that often the choice that seemed the scariest or the hardest was often the one I probably should have gone for. I have no proof of this because I so rarely chose them, but the ones I did choose rarely seemed to work out that well.