Warning! This is hypothetical!
Imagine that humans have upset the God Of Fastenings with our frequent swearing at zips sticking and when the drawstring knot comes undone and the end disappears into the material. She is very angry with us all and tells us that we are now only allowed one type of fastening for EVERYTHING, but we are allowed to choose which one. What would your choice be? (It wouldn't be totally down to you. I assume there would be a referendum.)
Zips? Buttons? Velcro? Poppers? Laces? Hook & Eyes? Toggles? Buckles? Other?