E-Z Soft Carabiner
Nothing could be easier to tie.
Use it as you would a light weight carabiner to hang or organize items.
Make a loop of the desired size and tie an overhand knot.
Slider Knot
Take a separate cord and tie an overhand knot tight around the loop. Leave a tag end for grasping.
I used a larger size cord because it shows up better in the photo.
A smaller diameter will work just as well and it would make it easier for smaller items to pass over it.
Put the overhand knot through the loop and snug the slider up against the overhand knot.