The first knot shown here, the Improved Clinch Knot, is my favourite knot for joining monofilament line to hooks and swivels – and it is super easy.
If you learn only this and the Palomar Knot (for tying braid to hooks and swivels) you have all that you need to tie a good rig and attach it to your main line.
You can learn others, but you don’t actually need to.
Three more knots for tying monofilament line to terminal tackle are illustrated below.
Learning any of these is entirely in the “up to you” camp – you can if you prefer one of them…