I love the look of soft light, but to make light soft, you need to make the light source large relative to your subject. The problem with large light sources is that the light goes everywhere and you may not want that.
I took some photos of Emma recently and used a medium sized Lastolite ExyBoz II with a pair of Speedlites in it as the light source. I’d positioned Emma close to a white wall to get a little fill on the shadow side of her face. Behind Emma was the corner of the room with another white wall.
Using my light with a grid gave me the result below. I could constrain the light so that it did not spread over and on to the wall behind Emma.
I then took the grid off the light, and took another shot so that you can see the comparison of the “with grid” and “without grid” versions. Without the grid the spread of light was much wider, but it did little to change the softness of the light, just lit a chunk of the wall behind Emma.
Next time you want to use big soft light, think about how you can control the light. For me a grid makes each of my soft boxes have more use as it can be used for more lighting situations.