The large lithium battery will last a very long time since the LED uses very little power and can be switched off when not in use. It's also surprisingly bright - bright enough that as well as being ornamental it could be used as a night light for a child, to find your keys or to dimly light a step to avoid anyone tripping in the night. You could also include a bag of potpourri, lavender or another fragrance and hang it up to scent your room.
Step 1: You Will Need...
For the star:
Alternatively, you can simply choose a decorative fabric, but felt is ideal since it won't fray
Needle and sewing thread
6 inches of narrow ribbon or thin cord
Stuffing or wadding
Beads for decoration
For the LED circuit:
Switched coin-cell holder
If you prefer you could use a Colour-changing LED kit - The kit, available from Kitronik.co.uk, includes the following -
Colour changing LED
You would also need a Sewable switch
Step 2: Making Your Felted Star...
Next, make a small hole where the LED will be on the front, and add beads as further decoration. (Pictured - Front star with the LED in place in the centre)
Step 3: Adding the LED...
The bulb has two wires attached, the longer one is positive and the shorter is negative. Use a small pair of pliers to bend the wires into loops which will lie flat against the back of the fabric, making sure you remember which one is which!
Next, push the bulb into the hole from the reverse side and stitch it in place using one strand of the conductive thread around the positive loop and one around the negative, being sure to wrap the thread firmly around the wire several times to make a good connection. I didn't want the bulb to stick out too far on the front of my star so I used a scrap of spare felt to space it back from the hole a little.
Step 4: Adding the Battery Holder and Switch...
Using the thread on the positive side, stitch around to the positive terminal on the battery holder, again making sure the connection is good by stitching the thread firmly around the terminal several times. Repeat the process with the negative thread, taking care that the two strands won't touch each other once the pieces are sewn in place.
If you chose to use a separate switch, or add more than one light, the sewable circuit is very forgiving for non-electricians! Provided the positive thread connects to the positive terminal, the negative to the negative, and the two don't cross or touch, you can't go far wrong, but there is a nice neat sample of a circuit with a switch and two LEDs here.
Step 5: Final Assembly...
Add a loop of ribbon to hang the finished star, and sew the two sides together, stuffing the star as you go along but leaving a space so as not to obscure the switch.