There must be six or seven different ways to tie the snell.
I recently changed how I tie mine after having one slip--my fault--the hook had been on the line for six months and didn't retie.
I'm a big fan of doubled line knots, so both of these are variations of the snell doubling the line through the eye.

How I used to tie it (good knot, just have to make sure it is cinched tight and stays tight over time)

How I tie it now