Improved Clinch Knot
This knot is a useful fishing knot that works well with thin monofilament.
1 Pass the running end through the hook eye or other attachment point, then make three to five wraps around the standing part.
2 Bring the running end back and thread it through the crossing turn closest to the eye.
3 Tuck the running end through its own bight. Tighten by pulling on the standing part. If there's slack, pull the running end.
Thin monofilament requires more wraps than thicker line does, and even one wrap can make the difference as to whether it slips under strain. It is difficult to pull this knot down when tied in thick line.