It's a bit tricky.. but not all that hard. Start with paper close to a golden ratio— I use 8.5 X 11, (which isn't really a golden ratio.. but its close enough. 8 X 10 will work too.
There is a lot of waste paper..but the perfect 5 pointed stars are so worth it!
Start with a peice of paper, fold it in half, (so it sort of looks like a book)
Keep the fold to the left.
The take lower corner of the book edge fold, and bring it up to the center top (the pinch mark
This crisp crease is going to be folded next. It will be brought up to the book edge fold--be careful 1) to not let the book edge fold slip as you make the third fold, and 2) make a sure it lines up starting at the lower point.. You'll want a crisp hard point.
Until now, the paper has been folded but not moved.. Now you turn it over and make the last fold. the top book edge fold s folded back and, if you've been careful up until now, the this fold will align on both edges, and yeild a sort of ice cream cone shape (a lopsided ice cream cone.
The cut line should be more or less parallel to the LONG edge of the top of the ice cream cone. A STEEPER line is better. Cut, starting at the top of the book fold, going down. (its 10 layers of paper so a sharp scissors are needed!)