Very easy to accomplish, you only need two rolling papers, a classic when you have finished the long papers and you only have short rolling papers.
Stick the two papers at 45 degrees as indicated. if you have narrow rolling papers better make an “L” i.e. stick the papers at 90 degrees.
Add a filter and your preferred mixture, the shape will facilitate the creation of a perfect cone.
While rolling the joint close the first paper.
Moist and close the second papers
here you are !!!