If you already own a hot shoe strobe you already have one of the most powerful tools for shaping light. Now, if you only took it off camera it would do a great deal to the final image. And you’d be surprised at how low of a cost it actually takes to move a hot shoe strobe off camera.
This video is definitely a strong demo of why moving a strobe of camera is such a powerful tool. Here are some photos to help see the difference.
This is the basic exposure, it sets the ambient light. even shooting at ISO 100, going with F1.4 forces a 1/3200 shutter speed
On camera fill flash (with HSS) added and opens up the shadows, but lighting is flat
Lastly the strobe is taken off camera (and moves to 1/5000)
Here is a quick comparison between no flash and off camera flash
and between on camera and off camera flash
Here is a rough cost calculation for you, even got spare for a visit at In and Out burger: