I used the instructions from here to start making them, but I thought that a picture format of all the steps would help others (mainly because it took me quite a few tries to figure it out on my own).
This is my no scissors approach to making these stars.
Step 1: Need
No scissors, so you need to also have a tongue.
Step 2: Measure
Measure and mark down the paper.
Step 3: Fold and Lick
You might not always have such on or near you, so here is what I learned as a young boy that works perfectly.
Fold the paper along the 1/2 inch line you drew. Try to get the fold evenly on the line.
Crease the fold with a fingernail all the way down.
Then, while it is still folded, run the fold along your tongue. For this your tongue needs to be slightly moist. Too moist and you will soak the paper, too dry and it wont work.
I did not get pictures of me using my tongue, hopefully you dont need a picture of that step. But if you do, just say so in a comment and I will get a picture up.
Once you have licked the fold, unfold it and tear along the line. I go at a medium speed, it tears apart perfectly, though not as cleanly as a pair of scissors, as you can see the paper fibers in the cut below.