I have had people ask me about my lighting when I shoot outdoors. It's not fancy, but it is effective, especially when shooting people and you want to avoid harsh shadows.
As most of you aware the built in flash (A) on most cameras is NOT very powerful. I often use a secondary flash (B) with a head that I can turn at an angle. Regardless of what brand you choose, you want it to be a "Slave" Flash.
When your original flash goes off, the sensor (C) on the secondary flash also sets that off. By keeping the more powerful light at an angle it keeps the image looking more like natural light (without blowing away the subject.) Since this light is higher and at an angle, you rarely see any additional shadows.