The Slim Beauty Knot is a great way to connect your main line (Braided) to your leader material (Mono, Fluoro, Copolymer). This is essentially tying a uniknot using the leader material onto the main line and then using the main line to tie the clinch knot onto the leader.
It works with line that are similar in diameter, but also does really well with thin mainline to thicker leader. but that will require a simple extra step... doubling the braided line and then tie the knot.
Notes:
For thin lines, use more wraps for both knots
For thicker lines, use two wrap uni-knot on the leader and less line on the clinch knot
When Leader is a lot thicker than the main line, Double up the main line and use less wraps while doing the clinch knot!
Enjoy the instructional video: