My First Ibble. Hope it's ok.
Simple to build, multiple uses.
Hope you enjoy.
All you need are four simple items.
A power supply for your LED.
A holder for the LED.
A check ring or washer.
And the Led Itself.

Step 1:

First thing you need is something to mount the LED in.
I used a left over wire reel, a small one you may have laying around the workbench.
As you can see you just need to slice off on end, and drill a hole large enough to run the LED leads through.
You could use lot's of things to hold the LED, use your imagination and what is at hand.

Step 2:

Here we have the LED unit mounted in the check ring.
For those wondering a Check ring is like a washer except it has a rim around the edge.
Again this could be something as simple as a washer, it just needs to have a center hole appropriate for the LED and a diameter appropriate for the mount.
The LED I used i got from Superbrightleds.com. It's in the component section as a color changing water-proof LED.
The LED end had a plastic Hex you unscrew. Then fit the LED through the hole and reattach the Nut.

Step 3:

Assemble as shown, run the leads through the hole you made in the reel.
In my case no adhesive was needed to keep everything in place. If you need it, a little glue, hot glue, or silicone sealer will keep everything snug.

Step 4:

Once you have completed the last step just Strip the ends of the wires from the LED and from the power supply and connect as shown.
Be sure to leave room for a little shrink tube for each pair and one for the whole joint.
Be sure to check your polarity or it won't light up.in my case the Power supply used the standard Red for + and Black for -
The LED however used the European color code, Tan for + Blue for -
Follow the steps in the pictures and once soldered and shrink wrapped your pretty well done.

Step 5:

The Completed unit, very simple to do.
Once completed you can put the LED mount inside a lot of different things.
In my case i used a Drilled out Selenite Crystal.
You could also use anything from a Milk glass lighting shade to and inverted fishbowl, or translucent plastic cylinder.
If you use something Clear consider filling it with a bunch of crumpled clear or frosted Cellophane, bits of clear plastic, Glass Marbles.
As long as it catches and diffuses the light you are golden.
All sorts of things can be used, subject only to your imagination,