A very versatile and often overlooked tool that can cost next to nothing is a simple TTL cord. With this cord you can get your flash off of your camera and still maintain your flash and camera communication.
One great trick that you can manage with a TTL cord involves High Speed Sync and a TTL flash unit. There are many companies out in the market that offer TTL flash units for the major camera brands and for the most part they are very capable and affordably priced.
These lower priced units normally do not offer off camera High Speed Sync functions but they are are capable of High Speed Sync when mounted on camera. So, what can you do to take these flash units off camera and still retain the High Speed Sync function? That’s right: use a TTL cord!
When using a TTL cord the flash is essentially still directly connected to the camera and will function just like it is still sitting on the camera body. Thus you will be able to use High Speed Sync with a TTL cord.
Theses TTL cords come in varying lengths from three feet to over twenty feet. If you need to you can also couple them together for longer lengths. If you are shooting an event one well used trick is to use a short TTL cord to connect your camera and flash and then hold the flash in one hand off of your camera to add some depth to your event lighting.
Another great use is with the longer cords. The flash end of the TTL cord will often have a ¼ x 20 thread on the underside of it so that it can be threaded onto a light stand or umbrella/softbox mounting bracket. With a long enough cord you are able to have your flash way off camera and still maintain all camera/flash communications.
With an affordable price, small profile, and large functionality for your flashes, TTL cords are a staple in my kit and an item that photographers should carry with them.