I embroider and crochet a lot. I make and sell kippot (Jewish head-coverings) and belts and wall hangings... and so I have a million different colors of thread around. But they get tangled if I try to cut off a piece from the way they're packaged when I buy them. Also, I live in Israel, am a grad student here for just one year, and subletting a furnished apartment, so I'm trying not to (a) spend any more money than necessary or (b) buy anything I don't really need so I don't have to get rid of it when I leave the country.
So here's how you can keep your threads untangled -- only using supplies that I would be very surprised if you don't have around your house.
Step 1: Materials
You only need a few things:
1. Some posterboard-weight cardboard.
I used the wrapping from a blanket I bought. You want it to be sturdy; an index card is too light (believe me, I've tried -- they just end up buckling!) and you can go as heavy as you want, so long as the thread can wrap around it well without being caught on anything.
3. The thread you want to wrap
I'm wrapping some DMC embroidery floss in this tutorial, but I've also used this method for wrapping regular crochet thread.
4. Optional: Hole punch
I like the option of being able to put my bobbins on a ring. But if you don't care, you can skip this one.
5. Optional: Pen or pencil
I like labeling the bobbins with the color code so I can replace it with the same one when I finish that bobbin.