Lighting 101: Umbrella Swivel Adapters
To attach your flash to a light stand, you'll need an umbrella swivel adapter. They are also called umbrella adapters, or just "swivels."
This pretty straightforward. These are rugged and cheap at about ($15). Top to bottom, here's how they work.
A. The Cold Shoe
Unlike a hot shoe, this has no electrical connections. It just holds a flash. (Or, in many cases the Universal Translator that would give your flash a sync jack.) Then you put the flash on top of that.
This cold shoe (on the LP633) has an expanding/locking clamp, which makes it sturdy and also lets it fit the foot of some weird flashes whose feet are slightly oversized.
B. The Umbrella Mount
This is a hole and clamp which holds the optical umbrella (more on that in a bit) which you will use to soften your flash's light. Even if you are not using an umbrella (which you will not do all of the time) you need this to attach a flash to a light stand, or anything els that is tipped with a 5/8" male stud.
You put the umbrella shaft into the hole and clamp down the screw. Pretty simple. If you are doing it right (i.e., not backwards) the umbrella shaft should point about ten degrees up (instead of down) to offset the fact that the flash is a little off-center due to the mount.
C. The Tilting Mechanism
I'll bet you can figure this out by yourself. You loosen it, tilt the flash and/or flash/umbrella combo, and tighten it back to lock in place. This model has a toothed grip for an added margin of no-slip safety.
D. The Light Stand Mount
This is the female receptacle and locking knob that holds the whole assembly to the top of your light stand. Or anything else with a male, 5/8" stud.
E. The Extra Stud
Some swivels ship with an extra stud. (The LP633 does.) This has a female, threaded ¼" x 20 hole at one end and a 3/8" hole at the other. With a little ingenuity and a bolt of the right size, you can figure out all kinds of positioning devices and/or brackets that might support a flash in a tight or unusual spot.
This stud will marry your frankenstein lighting creation to the swivel and allow you to connect it all together. Go nuts.
Next: Synching Your Flash to Your Camera