This is the detailing I did with a soldering iron. I don't think I did too well, but it looks okay for the most part. I'll probably add some brimming from some of the super thin foam sheets I have.
I also did some of the initial details with the soldering iron and as you'll see in the photo, it just doesn't work. My suggestion is to cut the details with your knife and open them with a heat gun. Way cleaner, and better control of where the details go.
As for the knife, I use a heavy duty Olfa with the black blades. They are seriously sharp.