One of these is the Half Blood Knot, which is more correctly half of the Barrel Knot. THIS KNOT WILL SLIP. It has cost me more fish than I want to remember.

If you must use it, then you have two choices:

a) Stop the end of the line with a simple Overhand Knot, and draw it against the turns of the knot.

b) or make the Half Blood Knot into a Clinch Knot.