This is supper easy.
This is all you need

first cut the paper to a decent size strip of card

cut it to a decent lengh

Fold the strap of cards into triangles and folding triangle in triangle

Then when you reach the end cut the end paper into a triangle

then where the gap on the big triangle is feed the small triangle in there

put presure on the middle down

Fold the sides and there you go.

Try it with card paper or even notes