Knots 3D – Learn how to tie over 150 useful knots
I took pandemic time to learn some knots, and then forget a bunch of them that didn't offer enough distinct utility to me.  I highly recommend the Farrimond Friction Hitch: https://www.animatedknots.com/farrimond-friction-hitch-knotIt's simple and fast to tie (with a little practice for muscle memory), and with an extra turn has exceptional friction preventing loop collapse in some situations where even a bowline would have an issue.  However, by relieving tension on one side of the knot, like a taut-line hitch it can slide.I use it for its common application of tensioning, but I also find it useful for cinching. It can go anywhere a cord lock might have been useful in but a few seconds.