On my recent trip to Old Car City USA I had some fun with my Speedlite and remote flash triggers. These pictures were taken in the middle of the day, but photographed to look like it was night time.
For the shot of the Ford Truck I set the camera white balance to tungsten and adjusted exposure to get the overall brightness I wanted.
Next, I attached a CTO gel to my flash. A CTO gel is a transparent, orange colored, sheet of plastic which is cut to cover the front of the flash. Any kind of transparent orange or yellow plastic cover will do. Mount it to your flash with a rubber band. Then the remote triggers were attached to the flash and camera. You need to use radio triggers rather than infrared triggers since you do not have an unobstructed line of sight between the transmitter and receiver.
Finally I set the flash to manual mode and set the power to around ¼. The zoom setting on the flash was adjusted to its widest focal length setting which was 24mm. The flash and trigger were then placed in the truck. A test shot was taken and the flash power was adjusted up or down to get the brightness level I wanted. Having TTL triggers makes this easier since you can make the adjustment from the camera. TTL triggers are significantly more expensive so you need to weigh ease of use vs. cost. Cowboy Studio and Cactus make inexpensive manual triggers which work well. Yongnuo has reasonably priced TTL triggers for Canon & Nikon speedlight systems.
The motel image was made in a similar fashion. The flash was concealed behind the debris in front of the tree and aimed at the sign. The zoom setting of the flash was set to maximum focal length, 105mm, to narrow the beam of light. You can see that I still had some light spill on the base of the tree. A snoot would have allowed me to narrow the light from the flash even farther.
This is just one of many ways to use white balance creatively. Have fun and experiment!