Most of my people photography is done on location and often outdoors. My #1 lighting accessory is an assistant with a big reflector (my #2 lighting accessory would be a second assistant with another big reflector or diffusion panel). The ugly truth is that there is simply no way to make a small, portable flash mimic the kind of light you get from a large, diffuse source. I've used the kind of "mini softbox" you mentioned--the improvement in the quality of light was marginal at best; if traveling, I wouldn't even bother with it.(posted 8352 days ago)The good news is that there's plenty of great lighting in the world out there that doesn't require any modification by you--you just have to look for it and utilize it. Light-colored cement or sand provides great fill. A newspaper works, too.
The best general advice that I can think of is to stop thinking about the accessories you have and other technical issues and start trying to see the possibilities in the available light.